[pirogen]

By "drawing from imagination" I meant drawing without a reference (live or otherwise). You point seems to be: "drawing a very realistic rendition of an object/subject without looking at it is hard". Which is true, but completely orthogonal to my thesis that "drawing from imagination == drawing from memory".

On a tangential note: there's more to creating believable art than accurate re-creation of proportions and details (which is why sites like deviantart are full of completely lifeless art that immediately reads as copies of photos). I'm aphantastic and only a have a very general idea of what a bear looks like, but I'm pretty sure I could draw a move convincing one "from my head" than someone untrained spending all day at the zoo would, because I have a good knowledge (or memory, if you will) of dogs and cats musculoskeletal anatomy I can extrapolate from, and I understand how forms in space and light work.