Is my iPhone being manipulated?

No your phone is not being manipulated or copied.

Check your Battery Health at Settings > Battery > Battery Health. That is one reason why you would experience the device turning off and unexpected behavior. That phone is only expected to last 500 charge cycles before needing a Battery replacement. That replacement should only be done by Apple or Authorized Apple Seller and a replacement by another location may result in a third party battery installed that is unable to meet the demands of the device.

Lee_iphonSE wrote:

Hi - something weird just happened with my iPhone SE. There was a ding and my screen turned black with some red on it and then it just disappeared as if I swiped it away. Anyone else experience this? I am afraid my phone is being copied or manipulated.

From your description it's impossible for us to have a clue what happened on your screen, but you have a higher chance of winning the lottery and being struck by lightning that you do your phone has been copied or is being manipulated. If you haven't jailbroken your phone, you have nothing to worry about on that. It could have just been some notification, which went away. If your phone is operating normally, I'd chalk this up to not much of anything.

Open Settings → Accessibility → Audio & Visual → Flash for Alerts. Check whether screen flashing is enabled.

Swipe down from the top of the screen to open Notification Center. See whether a recent notification explains the ding.

Check Settings → General → Software Update to see whether an iOS update is available. Don't erase or factory-reset the phone based on this incident alone.