The vaulted ceilings of the Chocolate Shoppe remind me of some in Grand Central here in NYC. I've always heard them called them the "Guastavino arches" after the designer--they are in GCT as well as downtown in the disused City Hall subway station (if you pretend not to hear the announcement to get off at the last stop of the Lex local, you can see them by staying on and riding through it). Anyway, back to L.A.... tourists are always hanging out in the corner of the arches in Grand Central, whispering--and it's clearly audible to a person listening at the opposite corner. You might try this the next time you're taking pictures in L.A.'s version...
NYPL
(Some pics of the [amazing] City Hall station
here.)