Luckily, a nice person stepped into the picture to provide a sense of scale at one of the face-tower gates to Angkor Thom.
The faces on the 23 m towers at the city gates (which are later additions to the main structure) take after those of the Bayon (main temple complex), and pose the same problems of interpretation. They may represent the king himself, the bodhisattva Avalokiteshvara, guardians of the empire's cardinal points, or some combination of these.
You can watch this excellent documentary:
City of the Gods - Angkor, Cambodia
for the architecture and cultural history of Angkor.
Angkor Thom, Angkor, Siem Reab, Cambodia.