Weird glitch

I had a weird glitch when using VLC media player.
Let me tell you what happened in what conditions:

- Windows xp
- a .flv video file.
- paint and every other image manipulation program.

Open .flv in VLC
Take PrintScr with the button on your keyboard.
Paste  in Img Manip. Program.
You can now watch the video in the program.

Sounds pretty weird.
I'll see I upload a video on youtube sometime.

Greetz!