Why is my finder icon slipping out of the dock?
iMac, OS X Yosemite (10.10.2), late 2013
Looking at your screen shot it looks perfectly OK to me.
No. Usually the Finder icon has the colored background too.
Anything change when you rebooted (Restart) your iMac?
Yes, it goes back to normal on reboot (or if I force quit the Finder). It's no big deal but I do wonder what it means, if anything.
Why is my finder icon slipping out of the dock?