Just tried a big movement up/down, yes, there is a difference, but, highs are lower both when i move headphone way high or down, seem like they work the same (verticaly) in most scenarios i use them on my head, but not horizontaly - i do need to place them in "sweetspot". Must be the Ears (and Head?), not Headphone.Not sure why it happens, probably for the same reason speakers sound different at angles and in different parts of the room (the airspace between the ear and driver being the room here).
Every headshape is unique I guess, I have a narrow jaw so when I pull the phones down, the bottom side of the cups move closer to each other and the angle changes.