Animated avatars and profile banners play everywhere, not only on profiles.
Avatar decorations and nameplates play on a loop instead of only when you press them.
Profile effects play when you open a profile.
Animated server icons and banners play in the server list, not only for the server you have open.
Animated emojis play in messages, reactions and custom statuses.
Animated stickers loop instead of playing once.
GIFs play on their own, without tapping them.
While it runs, Discord's own Animate Emoji, Animate Stickers and Automatically Play GIFs settings read as on for the parts you keep on here.
A port of Vencord's AlwaysAnimate.
Settings
Each part has its own switch, and all are on by default: Avatars, Avatar Decorations, Nameplates, Profile Effects, Server Icons (which covers server banners too), Emojis, Stickers and GIFs.