If someone's work is poor enough that a reasonable person might laugh at it, then there's nothing wrong with that. Hence the phrase "laugh at our mistakes". It doesn't mean you are a bad coder/painter, it just means you made mistakes that were a little funny and can learn from them like anyone else.

My team playfully makes fun of each other's code all the time. Every once in a while, someone does something stupid in code and we playfully make fun of that person, everyone on the team takes it in stride and our code is better for it.

Hell, every now and then I stumble across some idiocy in the code base and think "LOL, whoever did it this way is an idiot". git blame. "OH, hahaha, it was me, what an idiot past me was, amirite guys?" Everyone on the team takes levity about mistakes very seriously ;) It's healthy.

Mocking condescension on the other hand is a different thing entirely.

Is it? Or is it more like laughing at someone who built a table with 3 legs and wonder why it fell over? Or someone who fixed a car but forgot to put the engine back and wonders why they can't go anywhere?