Jim, I don't think it looks like he is promoting the breed in a negative manner. They don't have a sweet cuddly goofy look. They are powerful dogs. They should LOOK like powerful dogs. He is catering to the owners, not pet people.
I don't see the banner as being combative and warlike? Is it the fact it is black? APBT are not bichon's. Its kinda like when I have had non whipppet conformation class people pick my whippets tail up in the air trying to make it look like a sporting dog. I had to tell them to stop, it was wrong for the whippet breed.
I am sure some will be looking for sweet portraits and nothing smiles quite like these dogs!!
I think it's possible to show power without menace. The event banner is definitely (at least in my eyes) menacing.