The "trap" framing acknowledges the intent: the post is bait for attention and validation, and everyone knows it. Because it is usually self-aware and lighthearted, calling your own post a thirst trap defuses any vanity and turns it into a joke the audience is in on.
As content strategy, thirst traps exploit the engagement boost that attractive imagery reliably gets, and creators sometimes use one to spike reach before pivoting attention to a project or link. Used too often it can flatten a brand, but as an occasional tactic it is openly understood by audiences.