Whenever I see that Munn loop, I'm always drawn more to the parade of expressions that cross her face than what's in the lower half of the frame. There's a moment of dawning comprehension, then a flash of what looks like disgust, then an overcorrection into a forced playful response.
Oh, yeah, The Host was playful and fairly intelligent, but at the end it veered right off a cliff into that sort of tragedy the Koreans seem to love to include in just about everything. Not my cup of tea, especially when I can predict it.