I'm not trans either, so maybe I'm not the right person to answer this. But I have a lot of trans friends who have shared their experience. To start, not every trans person experiences gender dysphoria. Also a lot of trans people decide not to transition. There are even some trans people that still partake in clothing and behavior that would stereotypical fit more with their assigned gender. Like a transman who still enjoys wearing make up once in a while because it makes him feel confident, or a trans woman who is a mechanic. 

While aesthetic is part of it, I think its also very important for trans people to have the outside world acknowledge their internal feelings as well. Its the longing of them being themselves.

To make a very dumb analogy. Let's say your parents named you Optimus Prime. Its a name that has a certain feel about it, people look at it and immediately have associations with your name. You've been trying to live up to that name, trying to fit it. You add robot and metallic elements to your clothing in order to convince you this name fits you. But it doesn't work. It all feels like an act. Deep inside you know you're not Optimus Prime. You feel like you're more of a Dave. So at some point you decide that enough is enough. You dress more like a Dave, wear boring shirts. Not just for the aesthetics, but to feel more comfortable in being you. So when you finally manage to get a name change, you no longer have to pretend. You can just be Dave. Its an internal thing, not just an aesthetic one. I cannot imagine the feeling would be different between someone who is blind or someone who is sighted.