Some sellers make the feedback private on their buying account so people can't see what they've bought to flip.
The EBay note about the member having their FB private says the consequence of doing it is that you can’t sell. It doesn’t show any feedback at all. It’s not feedback with the item bought or sold as private. It actually says “no feedback”. She/he has 500+ FB’s with maybe 80 in the last 12 months but the feedback area is completely blank. Odd.