The clouds in the back are NOT smog! At the point this shot was taken, we had already exited the smog at lower levels. The fog in the back were blowing in and out with each cloud that were passing over the mountain.

If you didn't read the other post with the prayer flags and locks, the story behind the locks are that people hike to various points on the mountain and make pledges of love. The locks symbolize the fact that the two worlds of the lovers are locked for eternity for the gods to witness.