OK, so the child is patiently waiting to get stolen. I say 'patiently waiting'.... to me she looks creeped out as f**k, but I'm guessing some form of bribery or blackmail has been applied.
Anyway, those robots are genuinely working as a team, without guidance, to move her. This is 'swarm robotics', and one of the most iconic inspirations for it has to be this guy:
Lots and lots of different theories for how Skynet's shape shifting T-1000 might actually work have been suggested. But one of the most realistic is that he's actually a swarm of tiny robots co-operating - just like the child stealers above, but finer grained.
And, if that sounds unlikely, remember that nature has already set the precedent for how swarms can make almost any structure they need......