It’s not about Interpretation – no interpretation can happen here. This is about illustration of what is visibly evident – it must be visible. If the eye cannot see it, you do not draw it. You might realise that one bone slots into another, and so becomes partially disguised, but this no more entitles you to represent it.
As if you could imagine accurately the surface of the dark side of the moon, and accurately transcribe it. That would be some boast, and one filled with a measure of arrogance at that. You might sense these things, feel strongly about the existence of non-visible things.. but those things cannot be visualised as the eye would have it – Drawing is not the medium of the Invisible… what is?
Well, that’s another investigation, another thesis in that Question perhaps. Here, we use our eyes to ascertain the facts of the visible and physical world. We categorize those careful observations and we archive them through a Taxonomy. But no, it’s not about Interpretation, No. It’s about Accuracy and RE-Presentation of all the lumps and bumps, scars, blemishes and sinews.