Rumination.


You slow down slightly, restraining your avaricious desire to contemplate something that has been bugging you.
Why would there be a treasure chest here? Unguarded and in plain sight? It's not even hidden behind a wall, its just covered by a waterfall and that's transparent.
This must be a trap.
Your suspicions are confirmed as when you take a single step onto the tiled floor, a flurry of arrows fire out from the holes in the wall and continue doing so for a good while.

Soon the arrows stop, and give you a free path to the treasure.