There's cute jealous, and then there's Othello. Meaning, there's jealousy that everyone feels and is a natural feeling to have, but is virtually harmless when acknowledged that it's a normal human emotion, but not something to let destroy a relationship. Then there's extreme jealousy that stems from low self-esteem and a lack of confidence, and that has nothing to do with you. Your girlfriend's jealousy sounds irrational, and unless there's something else going on, it's completely unwarranted. I could see where she was coming from if you had cheated on her, but it doesn't sound like you have. Taking pictures with co-workers at an event is not crossing the line, in my opinion, and it sounds like your girlfriend is controlling and overly jealous. If it's this difficult after only 2 months, I think it might be worth it to cut ties. It's not going to get better than this, and it will most likely get worse.
"Caring is not an advantage."