That makes more sense, but that site actually says that clock moved. http://casa.colorado.edu/~ajsh/sr/time.html
What bothers me is that when you move away from the clock, your perspective changes. Do these figures take that into account? http://en.wikipedia.org/wiki/File:Time-dilation-002.svg
I don't understand this: http://casa.colorado.edu/~ajsh/sr/timevbig_gif.html
if the mirror is moving fast enough, why won't the light just miss it? why is the light traveling towards at an angle instead of straight?