Shiny arm??

So I broke my wrist, and my doc gave me a splint. Basically it’s hard plastic with Velcro to stabilize my wrist. When I took it off recently I noticed that my skin was SUPER soft and shiny. I’m not concerned or anything, I was just wondering why it was like this. Ik you can’t tell from the picture but my arm is soooooo soft. And it looks like there’s highlighter on it 😂😂

Also guys don’t worry, I was told that I can take it off sometimes!!!!