I think it is important to distinguish between what an object looks like as a whole, or at-a-glance, compared to what it looks like when your compile a half hour or more of accumulated observations across the entire object. This is especially true of subtle, extended objects like nebulae, galaxies, comets, solar phenomena, and planetary albedo features. This composite view is what many observers try to accomplish with their sketches. By spending ample time, gradually pulling numerous details from the object, an observer is able to slowly build up a picture that contains much more structure than a normal gaze will allow.
To demonstrate, here are some progressive images of a sketch I made of M17 a couple summers ago. To better convey the subtle impression of structures seen in the eyepiece, I've kept contrast low--so it will be helpful to view the images with as little glare on your screen as possible.
This first image shows how the nebula may appear at first glance: