That is rather bizarre. He can form a perfectly functional Bajoran communicator, but not a humanoid face?
And for that matter ... shouldn't his humanoid form have some attempt at nose ridges?
Then again, maybe that was his first form and he views it as his heritage. He could be perfectly capable of looking like a normal human or Bajoran and simply not want to, because that's not who he is.
His face is a lot more human[oid] in S1 - he just looks like an old man with some makeup on [
]. It's only later that he gets a more rounded, squishy face - a face that just happens to match the other Founders in their "normal" solid form. Even Laas, who has never met another Founder, has that sort of look to him (even though he matches his original finders better than Odo ever did).