You are going to hate me for saying this -
I think its a leather glove.
I have blown it up and you would normally get skin creases round the knuckles on a hand, the same as his other one, but there are no knuckle creases on the "gloved" hand. As for the fingernail, it is shadowed but there is no nail visible, so I would say its a pair of very fine leather gloves - or rather one very fine leather glove!
jc