Like I said, I think this creature will probably feature in the movie walking in the far back of a wide shot and for that it is just fine and it would be pointless to make it more detailed (like in the original SW, a lot of those background aliens would have looked horrible under closer inspection but they worked just fine as just a part of a background crowd). And I think this creature has been featured so prominently in that clip is because it's partly a joke and partly because they don't want to show us the good ones yet.