What happened to screen?

The photograph shows a failing display - and not a software issue. The only resolution is either a screen replacement (which, if outside of warranty may not be economically viable) or complete replacement of the iPad.

The best advice would be to take your iPad along to the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) where the technicians will be able to test and assess your iPad. After assessment, available options can be explored.

Genius Bar Reservation and Apple Support Options - Apple

Have you tried a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons?

Good Luck!

If this IS a hardware issues and IF this iPad model is an over 8-1/2-year old, 2012 iPad 4th generation, this iPad is NOT worth putting any significant cash into a repair.

Sorry.

Apple ended support for all 8-10-year old iOS devices well over 4 years, ago, in 2016.

Third party app developers abandoned and stopped supporting these 8-10-year old iOS devices nearly 3 years, ago, in 2018.

There are, virtually, NO MORE third party apps available from the iOS App Store, any longer!

Third party compatible apps for such old devices are few and far between, now, in 2021.

This includes apps for both iOS 9 AND iOS 10 devices!

Simply put, a 4th gen iPad is too old and obsolete now.

Sorry, but this is the reality for ALL 8-10-year old AND OLDER iOS devices now. Especially now in 2021!

It's 2021 now!

Time to seriously consider a purchase of a new iPad model OR a much, MUCH “newer” and less expensive, refurbished or used iPad models, from better known, trusted Apple product/device retailers/resellers, locally or online, on the Web/Internet, capable of running the latest iPadOS versions.

There are PLENTY of newer, older iPad models that can run the latest, current versions of iPadOS.

Sorry & Best of Luck to You!