Q: Screen colors distorted

Hi!

About 1,5 years ago my wife dropped her iPhone 4 on the floor, and since then the screen doesn't work, except for showing a thick line of colors in the middle.

I have now decided to have a go at it and am first of all trying to understand what part that is broken. Don't want to leave it to a repair shop since it would cost to much money for an old phone.

Does anyone have an idea what part could be broken just looking at the photos?

(The screen seems to react at touch of finger)