I "acquired" SC 1 a while ago and played it in dosbox, and I noticed something odd. In the captain portraits in SC 1 melee there are multiple frames of animation for each action, but in UQM there is just 2 frames, an on frame and the default frame. That is, in UQM it just flips the image from one to the other, whereas in SC 1 there is animation in between, so, say in the Androsynth portrait where they pull on a lever you can see them pulling the lever, while in UQM it just goes from not pulled to pulled.
Now I've never played SC 2 in dosbox, so I don't know if this is also missing from it, but I wouldn't imagine the graphics were downgraded from SC 1 to SC 2.
Actually, it seems like they very well may have been. I don't recall there ever being more than an on/off animation in any of the pilot pics in DOS SC2 (and can't say I ever noticed the additional animation frames in SC1 during my short stint with it, either).