Maybe they are just asking for a property release from the artist (who painted or drew the works originally). It's hard to tell anything from thumbnails, there may be details in full resolution.
It is probably an authorization to publish by the person who made these drawings. But sometimes the decisions are weird. For my part, I don't try to understand, I move on. That's what I advise you unless it's you who made these drawings. So just attach the authorization. The form can be downloaded here https://contributor.stock.adobe.com/static/releases/model/Releases-en.293128c8f1ff86abb874b5f73b8c50...
Adobe has no way of knowing who authored the artwork unless you sign and submit a property release, certifying that you are the creator.
as said Adobe does not know who draw this Art. So if you draw those by yourself it should be no problem to hand in those Releases together with the pictures in a good quality and all will be fine. Hope that helps.
There's nothing weird. You have to make a legal contract to say you own all the rights to the pictures, and everything in them (nothing copied etc.) A release form is how you do this. This means that Adobe then have the right to sue you if it turns out it was someone else's work - sadly this happens so often that Adobe must protect creators.
Just add a property release, saying that you are the creator of the nice patterns. Sometimes, moderators think that the artwork has been done by someone else (it is your creative work, isn't it) and then they will issue a refusal. It's nothing to be upset. Just do the paperwork.