Faces sell pictures. Obvious really considering there is a whole industry, advertising, partially dependant on that principle. Stick a pretty face in front of almost anything and you’re more likely to get it noticed.
The modern obsession with celebrity has complicated things somewhat but it is still true that some faces carry qualities that draw the attention more than others. and it’s not only prettiness. It’s when the concept of beauty comes in that things get complicated and interesting, because a face doesn’t have to be pretty to be beautiful. Other qualities such as innocence, vulnerability, cheerfulness, other-worldliness, authenticity, are all components of faces you want to look at.
Before photography whole volumes were devoted to physiognomy and the study of the meanings some faces convey but we are now a bit more sophisticated in our assessment. We no longer think, for example, that we can tell a criminal from their facial characteristics although the signs wrought by time, circumstance and culture can give us a good basis for judging who we want to spend time with.