That seems okay to me if the original artist has buy-in. But if the original art would normally be purchased, I wouldn't be satisfied to merely get a credit if I'm the artist.

Consider an equivalent example: If I go to Deviant Art and grab a pic that the artist is charging for (a common occurrence there) and slap it into my Medium story and then credit the author but not pay for the art, she could (and should) file a DMCA takedown request, which is the most common route for artists who can't afford an attorney.

So it depends on how Playground acquires its art. A credit is enough if an artist says it is.

Adobe just released a statement that their Firefly AI product uses only licensed art they pay for, and does not scrape from the Internet unless it's in the public domain. I'm surprised they don't include art with creative commons licensing, but maybe such art is too hard to extract programmatically across the Internet.

My experience with it is very limited, though.