There's a lot of chitchat on this plant on whether it is a pure walkeriana or actually some kind of hybrid. It is the same about Cattleya walkeriana var. alba 'Pendentive' (as far as I know, both 'Perfect Charm' and 'Pendentive' have the same ancestor, C. walkeriana alba 'Orchidglade', in their background, but 'Perfect Charm' is not from the same sow of 'Pendentive').
One cannot deny that the lip structure of these two shows some differences compared to the majority of the other walkerianas, but those differences alone do not allow to classify them as not pure.
My plant is a piece a friend gave me last year and is flowering in my hands now for the first time and I was curious about the perfume. The plant started to smell around 10 a.m. and the perfume is pure walkeriana.
Whatever it is, pure or not, it undoubtedly is a fascinating white!