It's like having a room entirely within a building, with no walls being outside walls. All the room's walls are interior walls. If you were to break through one of the room's walls, you would be in another room or hallways. Not outside. Now, if you broke through one of the building's exterior walls, you would be able to see inside the building and those inside would be able to see out. That's what a window is. Put a window in one of that interior room's walls, and you don;t see outside, you see the interior of the building still.
The suites of Mother of Song (third floor) and Mother of Grub and Mother Ukee (fourth floor) are all within the Tower complex. Their suites have windows that look out over the shadow fields and surrounding countryside. They can see clouds and sunlight, hear birds and dogs and wagons, smell the rain. Their windowsills get wet from the rain. But when you look at the complex from the outside, you cannot see any windows below the Tower's fifth floor due to the bottom four floors being within the rectangular complex. Ukee pointed out it's weird (to say the least) that everyone inside the suites can see and hear and feel outside stuff, but when they are outside the Tower, they can't even see the windows to the suite.
The garden that Mother of Builder likes to sit in is at the very rear of the complex, past the stable. But Ukee brought everyone to a hallway near the front of the complex with a wall only waist-high and arched openings that opened directly into the garden. If you climb over the wall and through an arched opening, you'd end up standing in the garden. But that garden and that hallway are separated by half the complex and the entire stable. So how can they be next to each other? How could Bevenlee hear the bumble bees doing their things? Or even potentially reach through the arched opening and touch a bee, or the flower it was on?
Same with the infirmary. It's on the ground floor. There are additional floors above it. The infirmary has no walls that are exterior walls-it's nestled within the complex. Yet it has windows that allow in sunlight and wind.
These are some of the weird things Ukee pointed out to Mother of Song, Sister Relle, and Sister Ynidi. And Bevenlee.
I don't know how else to explain it. Maybe it's just too weird from some.