Strange shutdown Yosemite 10.10.4

It's not much of a problem just more of an annoyance.
When I click shut down the screen dims slightly, the menu bar disappears but the dock drops half down. This then stays on the screen for about 5 seconds. Is anyone else getting this issue?

The screen looks more dimmed than it does on the photo.

I was getting the same issue intermittently. I dont know the source of the issue, and it seems to have stopped doing it for now...