Lots of the time, Blue Jay lays its crest down smooth, and it disappears. Then bang! it pops up, a flag waving for attention. The flag deploys when the jay is startled or excited. Or feeling greedy or ticked off or maybe amorous. And much more, I'm sure.
I try to feel my way into the into the mind of the jay, and sometimes I imagine I can almost read its signals.
But not quite.