The tutorial for the Island Sanctuary emphasises "visions" and then they are never used again throughout the actual gameplay.
Date & Time: any
Frequency: always
World name: any
Character name: any
Retainer name: n/a
NPC name: n/a ?
Monster name: n/a
Class/Level: any
Party or solo: any
In-game time: always
Area and coordinates: Unnamed Island
Housing: n/a
Steps:
1. Unlock the Island Sanctuary and work through the tutorial stage, which emphasises "visions" – basically, a quest displayed in the duty list, specifying a thing you can construct on your island and listing the materials you require to construct it.
2. Read the help guide in the Iskekeep's Index menu, which again highlights visions under the Basics section of the guide, describing them as "objectives in your duty list" that will unlock additional goals and features as you complete them.
3. Get past the tutorial stage, at which point you are given no further specific visions and do not seem to have any way of setting one. The duty list simply says "The Perfect Paradise: Create the island of your dreams" and that remains the sole listed goal for the entire time you are working on your island.
It seems like something may have gone wrong here. Is there supposed to be some way of designating an item or building as your current vision, and having its materials list appear in the duty list while you are gathering?