There is nothing stopping anyone from creating a TikTok clone, but there sure as hell are laws stopping anyone from directly ripping the UI (which Pixelfed did in this case).
Pixelfed used the exact same list of filter-names (image effects) as Instagram. Which is probably an oversight - I'd imagine its even a copy-paste from some hackernews/opensource/tutorial.
Neither the UI was ripped, nor the implementation cloned. It's all about the names used in a feature.
> copying actual IP.
This is exactly the problem they're facing.
PS; labels & text are part of the UI.
there is no "actual IP", just copyright, trademarks, user interface design elements, software patents and so on.
This is contradictory.