This page explains how to start and complete the Stalhorse: Pictured! side quest.
How to Start the Quest
Go to Snowfield Stable, which is northeast of Hebra Tower, and talk to Juanelle.
How to Complete the Quest
At night, if you go north from Snowfield Stable, until you are at the edge of the area, then go east, you will find North Lomei Labyrinth. Outside of the labyrinth, you can find Stalhorses at night. Take a picture of one, then go back to Snowfield Stable and talk to Juanelle to complete the quest.
Quest Reward
Juanelle gives you a Silver Rupee.