Pretty as a Picture

I was turning over sycamore leaves looking for larvae or pupae of the 16-spot orange ladybird when I found this small, 3mm, fly.  It is a picture-wing fly, sometimes called a wing-waving fly.  That latter name is because they can sometimes be seen shuggling their shoulders to move their wings around when stationary.

I usually try to give the scientific name of creatures that I blip but in this instance I found three different IDs that all seemed to match so I'll just leave it with its common names for now.