Social: Add the new media selection UI

[gmjuhasz]

Fixes https://linear.app/a8c/issue/SOCIAL-237/image-ui-create-the-image-view-ui-along-with-the-buttons

Sits on top of #46100

Proposed changes:

Adds a new unified media selection UI for social posts with the following features:

New NewMediaSection component

• Media source detection: Automatically detects and displays the current media source with priority order:
  1. Attached media (uploaded images/videos)
  2. Social Image Generator (SIG)
  3. Featured Image
• Dropdown menu: Allows switching between media sources (Featured Image, SIG template, Media Library)
• Media preview: Shows image/video preview with loading states for SIG
• Replace/Remove actions: Buttons to replace media via the dropdown or remove media entirely
• Analytics tracking: Records events when media source changes

Supporting components

• MediaSourceMenu: Dropdown component for selecting media sources
• MediaPreview: Preview component with action buttons for images and videos

Hook improvements

• Enhanced updateJetpackSocialOptions in usePostMeta to support batch updates, preventing race conditions when updating multiple options simultaneously (e.g., clearing attached media while toggling SIG)

Testing instructions:

Quickly check that with this PR and without the feature flag, you still see the old UI and it works as before.

Add the feature flag to your site: Run wpsh > add_blog_sticker( 'jetpack-social-unified-ui-v1', null, null, <your-blog-id> );

NOTE: Video upload is not hooked up currently

1. Go to a post editor with Jetpack Social enabled
2. Look for the new "Media" section in the Social sidebar
3. Test switching between:
   • Featured Image (should show post's featured image)
   • Social Image Generator (should show SIG preview with loading state)
   • Media Library (should open media picker)
4. Test the "Replace" button opens the source dropdown
5. Test the "Remove" button clears the media selection
6. Verify switching between sources works without glitches (no race conditions)

Source types

No image	Featured image	SIG	Custom image

Dropdown

Overlay menu

Edit template button

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Does this pull request change what data or activity we track or use?

Yes - adds analytics events:

• jetpack_social_media_source_changed - when user switches media source
• jetpack_social_media_removed - when user removes media

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the add/social/new-media-selector-ui branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack add/social/new-media-selector-ui

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

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Social plugin:

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 2 files.

File	Coverage	Δ%	Δ Uncovered
projects/js-packages/publicize-components/src/hooks/use-post-meta/index.js	23/24 (95.83%)	0.38%	0 💚
projects/packages/publicize/src/class-publicize-base.php	210/609 (34.48%)	0.43%	0 💚

5 files are newly checked for coverage.

File	Coverage
projects/js-packages/publicize-components/src/components/media-section-v2/index.tsx	46/61 (75.41%) 💚
projects/js-packages/publicize-components/src/components/media-section-v2/media-source-menu.tsx	23/24 (95.83%) 💚
projects/js-packages/publicize-components/src/components/media-section-v2/custom-media-toggle.tsx	4/4 (100.00%) 💚
projects/js-packages/publicize-components/src/components/media-section-v2/media-preview.tsx	3/3 (100.00%) 💚
projects/js-packages/publicize-components/src/components/media-section-v2/types.ts	0/0 (—%) 🤷

Full summary · PHP report · JS report

[grzegorz-cp]

Works well and the feature flag is respected.

To improve the PR, we could extract the colour hex to a variable in the SCSS file or use defined colours. We can also reconsider the file name from "new" to a version number e.g. - media-selection-v2, but it's not a big deal.

Thank you for breaking the work up into smaller PRs.

[grzegorz-cp]

I noticed that when a post doesn't have a featured image and you click "Featured image" in the dropdown nothing happens. We can improve this by adding a warning message or by disabling the option.

I would be great if at some point in the future, we could add a help popover that would explain all options available in the whole "Share to social media" sidebar. Currently using SIG is like a trial and error if you don't know what it does.

[gmjuhasz]

@grzegorz-cp I refactored the change a bit I found a better way to handle the logic. I also added the extra toggles here, as with this approach it made more sense rather than creating a new PR just for that.

I also fixed what happens when tehre is no featured image:

[grzegorz-cp]

Great, thanks for making the changes.