Simian is an adjective that means apelike or monkeylike. It's also a noun for monkey or ape. Either way, if that model overheard the comment (and knew what it meant), she'd likely sign up for lessons on how to walk the runway.
In Brave New World, author Aldous Huxley describes an elevator operator:
The liftman was a small simian creature, dressed in the black tunic of an Epsilon-Minus Semi-Moron.