You didn't do anything wrong...this kid snapped a picture of you....
He was stupid to do that.....and you can't feel bad for him...(I don't know if you do)....

If anything the Managers should be discussing with him that it is inappropriate to take ANY pictures at work. I"m sorry this made you sick mentally or physically.

Go back to work Monday...or whenever you are due back after holiday. If it is brought up again...than say what i just said to you...it was inappropriate of him...and you want them to make sure they make HIM aware of that. period.