I like the page-previews extension. This is a non-actionable comment on the feature. Please close me once you have read it and only if you agree some of these are reasonable, I can file more detailed, individual, feature-request tasks. Hope this is useful.
- The "gear" icon on the preview panel links to https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-rendering For me this is highly confusing, I think it should link to id #mw-prefsection-rendering-reading so the enable/disable preferences are on top.
- I love the behaviour of the panel, most of these dynamic elements are usually annoying, but I think I never was given an action I didn't want to perform. I am worried if people with limited mobility (disabilities, elder people, etc.) will have issues with it, and if it would be nice to allow optionally for a "slower" mode (where panel takes more time to disappear/mouse can be moved with even less precision). I love that it works without a mouse.
- This is not technically a page-preview thing, but a summary generation one. https://www.mediawiki.org/wiki/Page_Previews/Functionality#Basic_Functionality is a bit hidden, it would be nice that end-user documentation would be linked easier. I predict a lot of people asking "why is my text/image not showing". Maybe that bit can be copied into the 'Help:' namespace on Wikipedia. I wonder also if Wikidata could be used to decide an image in case of conflict?
- Could the feature be enabled at other projects on links towards wikipedias (e.g. Wikidata, but only for interwiki links, wikivoyage, but only for [[w: ]] links, etc.? That should be easier than making summaries work for other types of content (I am just guessing)?
- I feel the area that is clickable on the panel is strange- I guess it is only on the part that is 100% visible, and that a gap has to be added between the preferences and the button, but maybe the gap can be just a corner on the right-down, or at least extend the clickable parts a bit more towards the bottom part? Image attached: