He's missing a lot. I only see two skills that are NBA level, shot blocking and PNR D. Everything else is really below average.
Everyone knows he's badly undersized, but I'll add a few more things.
Soft...He looks a little soft to me. Doesn't seem to have much fight in him. You don't see much tenaciousness out of him. He's a very finesse player.
Athletic ability...He is supposed to be a very good athletic player, but I just don't see it. Can anyone recall when he's looked explosive and attacked the rim instead of throwing up soft runners (the latter part also speaks to his finesse style). Again, he should be a rim runner, soaring for rebounds type, but I haven't seen any of it, save for some of the shotblocking.
Motor...He doesn't really give multiple effort. At his size you need to have a Portis or Faried type of motor in order to offset that size disparity. Again, I just don't see it. A very passive unassuming player.