Chosen Solution

Have an iMac with a cracked display. I can’t feel any crack or unevenness on the screen but when I tap it, the screen jumps. Any help will be appreciated. Pics are attached. Thanks Update (06/23/2017)

Update (06/23/2017)

Here is what I have.

@ramadi that is a broken LCD. The only way to repair it, is by replacing it. Since you did not tell us which model iMac this is, start here to determine which guide you need.