It looks like a tractor... that is green?

Looks like the standard tractor found in the game. I don't know why it's green, maybe a mod (I doubt that it can be pimped) or a bug?

Some contect, the tractor randomly appeared on an intersection in the middle of the city. My two teammates weren't able to see it and for them I appeared to be hovering mid air. It's obviously the rusty tractor, but why is it green? Where did it come from? And why couldn't my mates see it? We were in an empty lobby by ourselves by the way. https://gta.fandom.com/wiki/Tractor

When looking back with green tinted glasses green tractors just look like normal tractors

I'm guessing it's a bug/texture glitch. Since your mates couldn't see it, I guess it was loaded by error or very likely by a hacker. Probably your game couldn't handle it and the texture loading for it went wrong because of that.

Looks like steam machine to me.