In this unknown place, with distinctly human construction, it's the best way he can think of to keep cover and still talk. They are in dire need of some information, it seems, even if neither can provide it.

Though the expression doesn't change, Optimus may very well have put a grimace in his words themselves.

"Are you unharmed? I saw you arrive, even if I do not understand how it came to happen." Still, the concern is obvious; the years apart have done nothing to change his protectiveness, it seems.