The Mystery in the Cathedral

Do you know what's going on in this picture? John sent it to me to ask if I could help him date the dress the woman is wearing (looks pretty early-1930s to me, or else set WAY in the Art Deco Future), but I'm so intrigued by everything going on in this photo (the box! the altar! the little-girl pages with swords! the priest!) that I asked him if I could post it and set y'all loose on the problem.

This is what John knows:

The photo was taken in the Cathedral in Fort Wayne, Indiana. The man is Msgr. Thomas M. Conroy, which dates the photo anywhere from 1921 to when the altar was changed about 1933 or so. No idea who the lady is, or what on earth they are doing, let alone in that gorgeous apparel. [ETA: the lady's name may or may not be Rosemary NEDILASEN or NEUBAUER.]

The photo above is pretty small; if you want to download a REALLY BIG one, that you can enlarge to see the detail on the box (a reliquary? an offering of some sort? a time machine?) you can grab it here. [UPDATED: here's a closeup of just the box.

My first thought was perhaps the woman was taking vows of some kind (to become a nun, or to join the Space Vestals -- I'm sorry, I can't pull myself away from that Art Deco Future) but John thinks that novices usually didn't wear so much makeup. Or so much velvet.

What do you think is going on? If you KNOW, that's wonderful, but in the meantime, idle speculation is encouraged.