NYC Anon here.
Went down into the subway under 666 Fifth last night. Didn't see much worth reporting, but snagged a few pics from an Art Shop down there, as well as some subway tile featuring the Red Cross:
Haven't seen that specific tile pattern in any other subway station that I can remember, but there's lots of stations in NYC. I know under the 23rd street station, where the Masons meet above, they have the square and compass embedded into the tile design.
There's likely tunnels and rooms behind that wall, as there were many service doors along it - most labeled for Subway maintenance.
Went into the lobby, no waterfall or sound of water - but the wavy ceiling was there.