That symbol has to come from some where, I thinking I saw it on some old statue or something similar. The hand diamond or pyramid, I think it look more as them trying for a diamond shape, too. Maybe it a star shape as in shining star, which is Lucifer. I do know I saw something Old with that symbol on it. I don't tend to make symbols myself, thumbs up yep that is one I do. The meaning of shooting a bird has changed since I was young, sometimes it was a joke, similar to sticking your tongue out at people. That is also another sign that means something else to other people.

When you see group of people doing thing together and keeps on doing it, and their actions tell what going on.

I remember why some people did this, there was something called the wave, they did their hand together similar to this and did up and down motion. Their thumbs cross over some though.