I think we're looking at the side, somewhere below the rib cage probably. So we see the border between the yellow front and the blue black, with a little white embellishment marking it, and then the grey over top is part of the sleeve.
So that gray and blue on the ride appears to be an inside part of the jersey flipped over onto the rest of the jersey. Could even be part of the arm with the blue part being a cuff. You can see the inside stitching on it. The blue part on the left is around where the shoulder blades are right about where the name patch would be. The yellow is the shoulder and neck area which then transitions to the front of the jersey which is all yellow. In fact I'm almost 100% sure that gray and blue part is the right arm of the jersey folded over onto the neck area of the jersey to not give it away.
Good god it really is a yellow in front blue in back monstrosity of a jersey.