These are famous ruins with a "happy face" on the wall above them. Man-made? If so, what does it mean?

I found a good little write-up online about these Mule Canyon ruins here
http://www.utahtrails.com/Backcountry%20pages/Mule.html
and will quote part of it:

The ruins you will see in Mule Canyon are between seven and nine hundred years old.
They are not part of any National Park, Monument, or Wilderness Area, and they have never
been excavated or restored in any way. The opportunity to discover these ruins in this
wild setting, with no rangers around telling you how to behave, is what makes Mule Canyon
such an exciting place. But with that freedom comes great responsibility. The ruins are a
precious national treasure and should be treated as such. View them with awe, but please
do not deface them in any way, and do not steal any of the pottery shards or other
artifacts you may find around them. Preserve them so that others may also experience
the magic of the canyon.