There is a walkway around the chapel, that takes you along the side on a raised platform and then you go in back of Our Lady where there are other things to see. Normally when there is not a Mass going on but Our Lady is exposed, the chapel is wall-to-wall people, and if you come with a tour group they will often have you and your group just walk on the walkway, you get like a 1 minute look at Our Lady and then you’re on to the next thing. Because if you had to get a chapel seat and then wait for her to be shown (they only show her at certain times, she’s covered otherwise) you would be there for hours and the tours don’t have time.
It’s sort of like the moving walkway at Guadalupe shrine, only it’s not moving.