I know most people on this site doesn't really know me, so most won't care, but i just made my new siggy about 20 minutes ago. [Look at post time of this thread.]
Yeah, that's the trick behind it. It goes to a random image every time you reload it. That Weeping Angel is there as a bit of a shock for those who look at my sig regularly. It's set up to appear much less often than the eye and all its stages of blinking.
I prefer full animations that don't require reloading, although mine are pretty Sh***y, and all i do is use sprite sheets ;3;
Well, it's not really supposed to be an animation. It's just a little easter egg for people who pay attention to details.