If set to "All My Plans", they will see everything even if they are not part of the plan. They will see all of your room reservations, FP+ selections, etc.
If set to "Only Our Shared Plans", they will only see plans that are included on.
You will need to set the option for each person in your family & friends list that has their OWN
MDE account.
We typically set it to "Only Our Shared Plans" for those NOT in our immediate family.
The PhotoPass setting is independent of the Plan Sharing option. If checked, that person will see all of your PhotoPass Photos.