Blue Jays will communicate with others Jays by the sounds they make, their body language, and the crest on top of their head; when they raise their crest up high that means that they are upset. When their crest is low, that is a sign that everything is OK. When the Blue Jays make loud noises, their crest is up high.
In one of the pictures, the Blue Jay on the right side was first on the log, but then another Jay shows up and the Jay leans away from the other Jay. That is a sign that the Jay on the left is up higher up on the social ladder. The Jay on the left side also let the Jay on the right side get a grape first.