This rooster has what I refer to as the 'domestic look' based on his feathering. We had some blues with great type and everything but the feathers were too soft and the roosters always had the wrinkled look in their tails. It took probably 6-8 generations of breeding to get rid of it once it was introduced and we still have it pop up from time to time in the blacks that were related to the blue rooster that had it. It seems like whenever someone introduced blue, they used a large framed bird that is what caused this. Too many people think bigger is better so we end up with these large birds that aren't very Sumatra like.
Sorry for the rant, I saw the pic and it is the perfect example of what I have been trying to describe to up and coming sumatra breeders about feather type and what to breed away from