Visiting friends

Why is it that sometimes when I visit a friend, all the pictures are locked? I cannot give them any help by visiting them....

The players are at a different level and have not unlocked these new pictures. Charge their desk icons in addition to pictures if you want to help your friends more when visiting. Hope this helps.

Thank you AnnD for your answer. However when this situation occurs, the only picture unlocked is the Venice one and there are no desk icons either on the table. I checked the player's level and they are no beginners.... This is not usual but it happens. Since it does not interfere with my game it's not that important but I was curious....