[Costin83]

I don't remember exactly how I did it but without the iFrame I was only been able to see the first frame of the video. I'm quite sure it wasn't the embed code that made the video to display.
And another drawback it was that the video would "display frames" in function of the background iFrame "refresh rate"
Try to tap mouse1 in the MOTD window as fast as you can with your experimental embed code... It should display video frames every mouse click... that's how I've got the idea of the hidden iframe... (with an auto refresh rate of "0")

[8088]

Oh, I think I misunderstood you. I see what you mean now. Yes, I noticed that clicking with your mouse inside the motd had an effect on the time/control bar, although it never occurred to me that it would actually play a frame when I did that. I'll give it a another try tomorrow.

[bazhenov93]

About the .GIF, not working to me, I tried it some months ago, and the gif is stopped (not moving).

[Costin83]

Odd as it may seem to be, I always had luck with ".gif" images. Never had a problem displaying an animated gif within the MOTD window...
And that being before I had ever tried the iFrame "hack"
The thing is that this was about 2 or 3 years ago when I had a server and I was messing with this kind of stuff...
I don't know if any further client update/s might have had broke the display of ".GIF's" inside of the MOTD...
From my knowledge, Steam it's notorious for breaking some things when they're trying to fix others...

[8088]

I just tested it with a refreshing iframe. Although the timeline progressed this time, there's still no visualisation.