When I post a photo of my miniatures, I personally expect constructive criticism. I'm an alright painter; not amazing and not bad, but improving is a good thing and I want to be able to better myself.
I find that posting photos and only wanting positive feedback is little more than requesting an ego massage, and that's not the purpose of showing off artwork in my opinion. There's nothing wrong with showing off some seriously well-painted models, but showing them off while seeking an echo-chamber of yes-men is just plain silly.
Of course you can't take it too far with critique and slam the paintjob unless they specifically ask for that level of analysis, but getting angry over someone suggesting a more subtle highlight or mentioning that the pupils are in an awkward place relative to the miniature's pose is just childish.