English to Russian Science Engineering (general) mmm... drawing

I would be grateful to anyone who helps me in getting the idea of the phrase "smth faces down the X-axis". It's related to the system of coordinates, with x-axis and y-axis in two-dimensional version, and the third, z-axis in three-dimesnional. Initially, I thought that, if we had a human model (digital art sculpture) that "faces down the x-axis" (as the specification for it states), then we'd have this axis starting inside (of behind) his head, going through his nose and going to nowhere parallel the model's sight-line. I hope the description is vivid enough :). But now as I can see the image with my mistake corrected - it's vice versa - the axis "the model is facing down" starts in front of the model's face and penetrates the face going from front towards back. Where is the truth, finally? Thanks in advance