The Bronze Garuda is the ninety-first treasure that can be found in Uncharted 2: Among Thieves.
The Bronze Garuda is found in Chapter 24 - The Road to Shambhala. Instead of examining the activated orb, you'll want to get a treasure in this room. Once you examine the orb, you'll catalyze a lengthy cutscene that will ensure you can't find this treasure, so be absolutely, positively certain you get this treasure first. Thankfully, this is an easy treasure to find and examine. Simply search the wall around you, and you'll no doubt spot the treasure's glimmer on the wall. Shoot it down with your pistol, and voila! Acquire your treasure on the ground.