There was a video someone posted years ago when this painting was unveiled. This is not that same video but goes to explain the reasoning. Sorry it's a youtube video but you only need to watch from the 30 second mark to hear the folks describing allah as having 2 right hands. The video breakdown that I cant find explains that at the time these texts were written, being left handed was considered sinister so to make allah perfect they invented the fact that he has 2 right hands. This painting is a nod to allah. Again this is according to a video someone posted years ago.