As far as I can tell, Pep has Gabriel play a little deeper than Kun, or maybe (which would be unlikely) this is something he naturally do without being instructed to. I get the feeling he has more defensive duties on his shoulders than Kun, which I would understand, and this would also automatically mean he will not gt into the same amount of scoring positions as Kun does.
I hope he is given time, and that he himself has the patience to stick around cause in a no too distant future, I think he will be our front of the line- striker, and I think he will be absolutely brilliant in that role.