There are 'point to point' measurements on a Unibody that get checked, and triangulated.
If those distances don't match what they should be, it means the body is racked or bent. (sounds like the tire shop noticed that)
Those repairs are done on a frame machine which is a platform onto which the vehicle can be clamped. It also uses hydraulic rams which will pull specific anchor points that the body has back into alignment.
It would be nice if it was as simple as a bent control arm; though I think the tire alignment shop would have fixed it, if it was that easy.
This should be interesting.