Everyone has pretty much told you what's weird about it, do a little more work and people are probably going to give you an edit. Not everyone likes doing edits. Some people like drawing diagrams and reference images. Here's something that could help.
Flat <<-- -->> Not Flat
The flat screen is of course flat. The not flat screen isn't flat, it has a lens shape. It looks like you have a flat frame with a lens screen instead of a flat surface.
So just imagine the shape like this
It's just a thin box. the screen doesn't bend or "bubble" out. It's flat. Making it a flat screen.
Well I hope those help. If they don't, use google.
