“..In a corner of Washington National Cathedral, several hundred Muslim worshipers..”
hummmmmm? In a corner- the National Cathedral is a huge edifice. In the corner? could that be a chapel?? They weren’t up where the pulpit,choir and altar area are located - the heart of any church?? Curious?
Probably in a transept area. There really is not much furnishing there, it is easy to adapt whole large areas because they are barren floors.