And what's your intention of posting a pic of his doing this, if I may ask?
Why not try a different approach. Go to him and start a friendly conversation:
You: Hey I saw that you're taking some pictures of the class with a nice looking DSLR. How did the pictures turn out?
Him: Oh hi. Erm.. ok, but some of them look not very clear.
You: Ya it is hard to take pictures indoor. Normally if I get blur pictures I will try this technique. (And you show him how to do it).
You: Why don't you give it a try?
Him: (After taking a few shots). Hey that is indeed better, thank you very much bro!
Isn't that much better then posting his pic here showing everybody how bad he had done without his knowledge?