These people often will try to get a Discord or another mean to privately DM you so they can share more "examples", most of which are stolen. They don't post these publicly in order to not be found. You can see an example of that here (again, with @zephyrbug.bsky.social 's art)

always google image search the stuff they send

ah good memories :,)

Those "preview" watermarks (always Comic Sans or Arial), or "awaiting client approval" et al, are a dead giveaway.

If you get art DMed as examples from a suspicious person (often when you didn't even ask for it), always try to ask to other artists if they recognize it, or do a reverse search. They often watermark it so you can't find anything, but it sometimes work!