Corrected entry: Tony starts the movie with putting a number of sensors into his body, so that the Mark XLII knows where he and his limbs are. But neither Pepper or Killian have these sensors (it is ridiculously unlikely to assume otherwise) and yet the suit assembles perfectly fine on them as well.
Friso94
2nd Jun 2013
Correction: The sensors injected into him allow him to remote control his suit. Not just follow him. it allows him to send it anywhere.
MasterOfAll