You really get this gif after two days without sleep, believe me

How?

Shine bright like a diamond

This is giving me a headache, but I can't stop watching

Does it get faster the more you watch it, or is it just me?

The only thing I'm getting is a seizure.

You should have put this as NSFW and posted "Seizure Warning" in the title.

Can it be any brighter?

This is only like, 3 frames. They use special effects to make it loop, even though it's not necessarily 'looping' either. I think the flash has something to do with it

I think the trick is that every time it changes colors, the dark parts are light and the light become the shaded part, making our brains think there is a lot of movement happening. I dont think the diamond is actually moving...