Course. Here I'll break it down what I mean. Its going to be long so sit tight and buckle up.
Derek does his collages in a quick pace so there's a lot of looseness to his approach, almost abstract like when you look up close.
He doesn't focus on a strict line structure like you do. The hair, eyebrow, eye lashes, lips in your collage seems like deliberate cuts to give it that structure while Derek does not do any of that deliberate cutting to fit an eye lash for example. He said he doesn't use any cutting, only ripping.
I also notice you use worded pages to make up the face, which is not apparent in Derek's stuff. Now what is really striking to me is the shading/ structure style that you use that brings out the face that is way different than Derek's. It reminds me of those really high quality noir style cartoons. I especially like the nose/eye area with the shading to make it not look flat. I also think Derek's style is way up there so it is very difficult to come close to what he does.
Wow... that's a pretty long feedback, you've written. Thanks for this, that's my first real feedback I've ever got her on dA.. You really pay attention to details, I like that, because many people just see something as a whole and they don't see the details. I take this feedback as a huge compliment, you really made my day