Before, no explicit border (which I disliked), a more 'embossed' look, and the indicator for the expansion was not that icon IIRC, if present at all.

Change 683777 had a related patch set uploaded (by Isarra; author: Isarra):

[mediawiki/skins/Timeless@master] Support mw 1.36/1.37: Disable all skin features except for a couple in favour of mw 1.34 shared.css to avoid weird inconsistent visual styles

https://gerrit.wikimedia.org/r/683777

Change 685614 had a related patch set uploaded (by Jdlrobson; author: Jdlrobson):

[mediawiki/core@master] Legacy feature should not load thumbnail style rules

https://gerrit.wikimedia.org/r/685614

^ Based on your feedback here. @Izno @Isarra does this have the desired effect? If so I can backport to 1.36.

Change 683777 merged by jenkins-bot:

[mediawiki/skins/Timeless@master] Support mw 1.36/1.37: Disable all skin features except for a couple in favour of mw 1.34 shared.css to avoid weird inconsistent visual styles

https://gerrit.wikimedia.org/r/683777

In T280292#7064201, @Jdlrobson wrote:

^ Based on your feedback here. @Izno @Isarra does this have the desired effect? If so I can backport to 1.36.

Is the legacy feature still being deprecated? If so I'm not really sure I see the point doing anything there specifically...

Also still can't actually use 'legacy' in Timeless unless all the other features with monobook styles are also removed/have their boxes separated out, but even this seems like it might be good to backport to 1.36 as is for better backwards compatibility for such skins in general at this point.

So that actually would be a good step toward T280723, at least?

The legacy feature is still being deprecated but as with any other deprecation we have been trying to do this in such a way that skins can take the year or two they need to cach up. If a skin is using legacy, minor padding changes and a border here and there might be okay, but this one does seem like a substantial unwarranted change which changed look and feel following further investigation (in short you've convinced me).

I am still not sure what else is a problem with T280723 but let's focus on this one for now :)

@Jdlrobson says this should block the 1.36 release.

Change 690085 had a related patch set uploaded (by Jdlrobson; author: Jdlrobson):

[mediawiki/core@wmf/1.36.0-wmf.36] Legacy feature should not load thumbnail style rules (only layout)

https://gerrit.wikimedia.org/r/690085

Change 685614 merged by jenkins-bot:

[mediawiki/core@master] Legacy feature should not load thumbnail style rules (only layout)

https://gerrit.wikimedia.org/r/685614

Change 690085 abandoned by Jforrester:

[mediawiki/core@wmf/1.36.0-wmf.36] Legacy feature should not load thumbnail style rules (only layout)

Reason:

https://gerrit.wikimedia.org/r/690085

Change 690797 had a related patch set uploaded (by Jforrester; author: Jdlrobson):

[mediawiki/core@REL1_36] Legacy feature should not load thumbnail style rules (only layout)

https://gerrit.wikimedia.org/r/690797

Change 690797 merged by jenkins-bot:

[mediawiki/core@REL1_36] Legacy feature should not load thumbnail style rules (only layout)

https://gerrit.wikimedia.org/r/690797