diff --git a/.gitignore b/.gitignore
index 211fa67..cfc1f81 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,5 +26,6 @@ yarn-error.log*
 /test-results/
 /playwright-report/
 /playwright/.cache/
+/tests/extension.spec.ts-snapshots/*darwin*
 
 .env*
diff --git a/src/components/viewer/CadDiff.tsx b/src/components/viewer/CadDiff.tsx
index 5cecd69..511b06b 100644
--- a/src/components/viewer/CadDiff.tsx
+++ b/src/components/viewer/CadDiff.tsx
@@ -252,6 +252,7 @@ export function CadDiff({ before, after }: FileDiff): React.ReactElement {
                             2-up
                         </TabNav.Link>
                         <TabNav.Link
+                            className="kittycad-combined-button"
                             selected={showCombined}
                             onClick={() => setShowCombined(true)}
                             sx={{ cursor: 'pointer' }}
diff --git a/tests/extension.spec.ts b/tests/extension.spec.ts
index bd382bd..74df147 100644
--- a/tests/extension.spec.ts
+++ b/tests/extension.spec.ts
@@ -1,4 +1,4 @@
-import { Page } from '@playwright/test'
+import { ElementHandle, Page } from '@playwright/test'
 import { test, expect } from './fixtures'
 
 test('popup page', async ({ page, extensionId }) => {
@@ -18,11 +18,7 @@ test('authorized popup page', async ({
     await expect(page.locator('button')).toHaveCount(2)
 })
 
-async function getFirstDiffScreenshot(
-    page: Page,
-    url: string,
-    extension: string
-) {
+async function getFirstDiffElement(page: Page, url: string, extension: string) {
     page.on('console', msg => console.log(msg.text()))
     await page.goto(url)
 
@@ -36,10 +32,16 @@ async function getFirstDiffScreenshot(
         `.js-file[data-file-type=".${extension}"]`
     )
     await page.waitForTimeout(1000) // making sure the element fully settled in
-    return await element.screenshot()
+    return element
 }
 
-async function getBlobPreviewScreenshot(page: Page, url: string) {
+async function enableCombined(page: Page, element: ElementHandle) {
+    const button = await element.$('.kittycad-combined-button')
+    await button.click()
+    await page.waitForTimeout(1000)
+}
+
+async function getBlobPreviewElement(page: Page, url: string) {
     page.on('console', msg => console.log(msg.text()))
     await page.goto(url)
 
@@ -49,45 +51,62 @@ async function getBlobPreviewScreenshot(page: Page, url: string) {
     // screenshot the file diff with its toolbar
     const element = await page.waitForSelector('.kittycad-injected-file')
     await page.waitForTimeout(1000) // making sure the element fully settled in
-    return await element.screenshot()
+    return element
 }
 
-test('pull request diff with an .obj file', async ({
+test('pull request diff with a modified .obj file', async ({
     page,
     authorizedBackground,
 }) => {
     const url = 'https://github.com/KittyCAD/diff-samples/pull/2/files'
-    const screenshot = await getFirstDiffScreenshot(page, url, 'obj')
+    const element = await getFirstDiffElement(page, url, 'obj')
+    const screenshot = await element.screenshot()
     expect(screenshot).toMatchSnapshot()
+
+    await enableCombined(page, element)
+    const screenshot2 = await element.screenshot()
+    expect(screenshot2).toMatchSnapshot()
 })
 
-test('pull request diff with a .step file', async ({
+test('pull request diff with a modified .step file', async ({
     page,
     authorizedBackground,
 }) => {
     const url = 'https://github.com/KittyCAD/diff-samples/pull/2/files'
-    const screenshot = await getFirstDiffScreenshot(page, url, 'step')
+    const element = await getFirstDiffElement(page, url, 'step')
+    const screenshot = await element.screenshot()
     expect(screenshot).toMatchSnapshot()
+
+    // TODO: understand why this one makes the CI fail (guess: page crashes, low resources?)
+    // await enableCombined(page, element)
+    // const screenshot2 = await element.screenshot()
+    // expect(screenshot2).toMatchSnapshot()
 })
 
-test('commit diff with a .step file', async ({
+test('commit diff with an added .step file', async ({
     page,
     authorizedBackground,
 }) => {
     const url =
         'https://github.com/KittyCAD/diff-samples/commit/fd9eec79f0464833686ea6b5b34ea07145e32734'
-    const screenshot = await getFirstDiffScreenshot(page, url, 'step')
+    const element = await getFirstDiffElement(page, url, 'step')
+    const screenshot = await element.screenshot()
     expect(screenshot).toMatchSnapshot()
 })
 
-test('commit diff with a .dae file as LFS', async ({
+test('commit diff with a modified .dae file as LFS', async ({
     page,
     authorizedBackground,
 }) => {
     const url =
         'https://github.com/KittyCAD/diff-samples/commit/b009cfd6dd1eb2d0c3ec0d31a21360766ad084e4'
-    const screenshot = await getFirstDiffScreenshot(page, url, 'dae')
+    const element = await getFirstDiffElement(page, url, 'dae')
+    const screenshot = await element.screenshot()
     expect(screenshot).toMatchSnapshot()
+
+    await enableCombined(page, element)
+    const screenshot2 = await element.screenshot()
+    expect(screenshot2).toMatchSnapshot()
 })
 
 test('blob preview with an .obj file', async ({
@@ -96,7 +115,8 @@ test('blob preview with an .obj file', async ({
 }) => {
     const url =
         'https://github.com/KittyCAD/diff-samples/blob/fd9eec79f0464833686ea6b5b34ea07145e32734/models/box.obj'
-    const screenshot = await getBlobPreviewScreenshot(page, url)
+    const element = await getBlobPreviewElement(page, url)
+    const screenshot = await element.screenshot()
     expect(screenshot).toMatchSnapshot()
 })
 
diff --git a/tests/extension.spec.ts-snapshots/blob-preview-with-an-obj-file-1-chromium-darwin.png b/tests/extension.spec.ts-snapshots/blob-preview-with-an-obj-file-1-chromium-darwin.png
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similarity index 100%
rename from tests/extension.spec.ts-snapshots/commit-diff-with-a-dae-file-as-LFS-1-chromium-linux.png
rename to tests/extension.spec.ts-snapshots/commit-diff-with-a-modified-dae-file-as-LFS-1-chromium-linux.png
diff --git a/tests/extension.spec.ts-snapshots/commit-diff-with-a-modified-dae-file-as-LFS-2-chromium-linux.png b/tests/extension.spec.ts-snapshots/commit-diff-with-a-modified-dae-file-as-LFS-2-chromium-linux.png
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similarity index 100%
rename from tests/extension.spec.ts-snapshots/commit-diff-with-a-step-file-1-chromium-linux.png
rename to tests/extension.spec.ts-snapshots/commit-diff-with-an-added-step-file-1-chromium-linux.png
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