The workshop preview.jpg file actually support other image formats in the Steam client, but the game still only supports some of the Exif and JFIF headers, it else displays a red "?" for the preview in-game. For an example see https://steamcommunity.com/sharedfiles/filedetails/?id=2337746040&tscn=1610113049 , which renders a gif just fine in the Native client, but no once you start a "new scenario". (I actually just renamed the gif to jpeg and rely on the app reading the header, I hope I did not over-think this.) The decals feature has support for gif87 and gif89 format, particularly animated gifs as works in decals. Is this a big piece of work, to make workshops really stand out. Note you are still limited to 1Mb in a gif in the steam workshop, but as you can see from above, it's not hard to do a decent job in 1Mb.
Not only the preview but also in the description.... Upload Animated Workshops (WORKING) How to Animate Your Workshop Showcase
Now that I have you, it's completely unclear to me what this actually does, care to explain what this accomplishes? These guides (other ones) by the same author linked have helped me a lot, but this particular one is complete waffle to me. ... 1. Accept Workshop Legal Agreements. 2.⠀Visit this link in a browser: steamcommunity.com/workshop/edititem/767/3 3.⠀Right click anywhere, inspect elements, and go to the console tab. 4.⠀Paste this code in the console and press enter:$J('#ConsumerAppID').val(480),$J('[name=file_type]').val(0),$J('[name=visibility]').val(0); 5.⠀Close the console, fill out the page, and click save. 6.⠀You've successfully uploaded your animation. ... Are you saying that if I do this, I have to manually upload a gif every time I do an update? I did not do any of this, so a bit lost as to what you are saying here. I'm missing some context. My problem with so many Steam guides is that they often work, only if you are speaking the same language and use the same tools. Made no sense to me at all.