Employ stationary background images on login page.
I find the moving background images on the login page very annoying while trying to enter my name and password.
Judy Miskin commented
It bothers me as well, but I am concerned with people who have seizure problems. The moving screen could be a major issue. When I was younger I suffered from motion sickness and a screen like that would be difficult. I wasn't going to deal with the issue but obviously people have difficulty, especially when signing in.