Honestly, the dog is the most interesting character and thats in the comics too, not just this trailer. Only the dog Lockjaw and Black Bolt (the king) were ever B-list characters, the rest of the Royal Family were C or even D-list and never all that popular.
This show is just lazy, you may recall from Agents of Sheild that some Inhumans come out 'weird' - like the eyeless teleporter Gordon, spikey Raina or the monstrous Lash or Hive. We see none of those mutations in the Inhumans on the moon, no centaurs or butterfly women, only a line of plebs who look more like Alpha Primitives than the rightful nobility of Earth.