A non-sucky YB pic (belly shot):
To the OP, read carefully. Your YB is not of the same colouration as the one preduced by me here, but that's just due to the line I'm working with.
LOOK at the area when the pattern meets the belly- even on sucky YB (or sucky pics) you'll note it almost looks pixelated like a low-res you-tube video. Your snake is a YB. I suggest you get to know the attributes on the morphs a bit better BEFORE you buy.
Too simple ask in advance what to look for- there'e enough of us here to help with that.