There are always a few students who do not like thier pictures taken, they hide or have to do something goofy during the picture.
I used to take a class picture after the first week of class. Many students did liked it.
I would make a few copies on our black and white printer on plain paper and pass them out.
What is harder is taking individual pictures. I won't try that one again! Some students flat refused to have thier picture taken.
Most students liked a class picture but I dropped the practice because of the objection of a few.