It is an EOTECH holosight. That one runs on two AA cells. My personal favorite.

 It is on correctly. Though I prefer mine a bit further forward. This is FACT. I have owned many. The control buttons are facing the shooters face as they should. His rear sight is down...No big. If it's sighted in just put the dot on the target. Having the front (In this case the front sight is a fixed type) and rear sight in alignment with the holo sight is called co-witnessing.

Please!!!!!! If you're going to publish stuff like this. Make sure you know what you are talking about. It makes us real gun folks look bad.

Ha, ha, ha, ha, ha, ha, ha, ha, ha, ha...................