Item description:

What you're doing is using the lenses and mirrors
in the pool below to direct all three ray beams
onto the mosaic, in order to open the temple.
It's difficult to explain all the moves for it in text

Sometimes if a mirror spun around and didn't connect with another
when you let it go, you could aim it a little to the side of the
second mirror you were pointing it at and it would connect

Best to watch the vid (From 15:05): [ Register or Signin to view external links. ]

Note: Copy each move very carefully!
If you make a mistake or let go of a mirror,
quit out to the main menu, and restart
You'll start off right before you began the puzzle
(Or Reload My Save Just To Be Sure)

Once you've completed the puzzle the mosaic will open and reveal itself
to be a gate.... "Raiders Of The Lost Temple" trophy will pop

The temple is below

When you regain control of Kate, climb down the diving platform and
then down to the pool using the ladder, then follow the Youkols
into the temple.... "O Spirits, Are You There? trophy will pop