Reflects light

Exploration Stage: Hall of Weddings
From: Cardsharp
Description: Rainbows are seldom seen because the sun is usually hidden when it rains, so if it works that well, you won't have much trouble. So all we need is a big reflector. That's a piece of cake for you, isn't it? You use it to reflect the sun's rays, and you get a rainbow.
Completed: The surface of this reflector shines and reflects well! So, I'm assigning you to operate this reflector. This is a very important mission to find the treasures of the Leprechauns, so please do me a favor.