Fav! This is quite beautiful -- I don't understand low-key enough to know how to read the histogram for values which is what I think it has to do with, but it doesn't matter what the label is -- definitely seems low-key in the lighting and darker tones, and it's stunning.
I am no expert, but I'd say it qualifies as low-key. The lighting is very subdued and even the colors are in the darker range so I think it's pretty close! Very nice!