This page explains how to start and complete the Guardian Slideshow shrine quest.
How to Start the Quest
The quest giver is on the east side of the mouth of the Menoat River, which is south of Lake Tower. The quest giver is on the west side of Puffer Beach. One way to get there is to go west on the road from Ka'o Makagh Shrine, and keep going west to reach Harfin Valley. Don't cross the land bridge that goes over the Menoat River. Instead, go south along the east bank of the river. Go south on the beach and continue going along the beach until you see a dead Guardian.
Just beyond the Guardian, talk to Loone to start the shrine quest.
How to Complete the Quest
Loone wants to see flying Guardians, small Guardians, and walking Guardians. You need to take a picture of a Guardian Skywatcher, Guardian Scout, and Guardian Stalker. When you take a picture of a type of Guardian that will count for this quest, there will be a red exclamation mark in the picture.
To get a picture of a Guardian Scout, you can go into any "test of strength" shrine. For example, you can find the Pumaag Nitae Shrine (A Minor Test of Strength) north of Ka'o Makagh Shrine. Or just check the list of shrines and search for "test of strength". If a test of strength shrine is empty, you can wait until the next Blood Moon to fight the Guardian in that shrine again.
Guardian Skywatchers can be found northwest of Tena Ko'sah Shrine, or around Akkala Tower, or around Hyrule Castle, for example.
There are many Guardian Stalkers around Hyrule Field, and you might be able to take a picture of one from the top of Central Tower. Otherwise, you will eventually find a Guardian Stalker if you go east from the quest giver for this shrine quest.
After you have a picture of a Guardian Skywatcher, Guardian Scout, and Guardian Stalker, go back and show Loone the pictures that you took. If you show her all three, she will let you take the orb. Pick it up and put it into the shrine pedestal to make the Shoqa Tatone Shrine appear.