For perspective: This is actually the hand of Mark Brooks who is the artist that created the Spiderman Tron variant.
The grey-scale image and the hand comparison helps a lot but there is no doubt that this can be confusing. To think this is the right hand makes sense. If it is the left hand, the spiderweb is held odd and the thumb is underneath the fingers. Also worth noting that one of the ovals overlaps multiple fingers but stays intact.
For anyone who thinks this was an easy one to see, the artist has commented on this multiple times simply because it IS confusing.