In James’s blog post about how people look at other people’s faces, he described how we are not only attracted by other people’s faces, our attention is also drawn to what other people are looking at. In short, we look where they look.
This is a particularly useful behaviour to act on if we’d like to draw a user’s attention to certain things.
Have a look at this scene in the ad:
Coincidence? I don’t think so. The ad does the same thing a few more times in the same ad:
UX Guideline #102: Draw users’ attention by using images with faces looking at your call to action or message.