Doesn’t REALLY matter what stimulus you draw from. Drawing is an eye-brain-hand skill and you can place the emphasis in whatever aspect of that you want to.
Drawing has different purposes. If you want to use it to ‘accurately’ depict reality (an impossible aim) then observational drawing from real objects is obviously where you develop your skills.
In its purest sense though, drawing is making marks on a surface. To do this in an interesting and visually exciting way it really doesn’t matter whether you draw from imagination, a photograph or reality.
slainte ➡ rob