Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
That screen indicates that the firmware/software of your iPhone is corrupted. This usually happens if the phone is interrupted during the update. Your need to restore the iPhone software through iTunes application (from computer)
But if you've backed up your iPhone to iTunes on your computer or iCloud, then you can restore all your data back after restoring your iPhone from iTunes/iCloud. You can also redownload all your past purchases for free using the same account.
Follow the steps below to restore your iPhone from your computer.
First download and install latest iTunes on your computer from here : https://www.apple.com/itunes/download/
Then connect the iPhone to your computer with the USB Cable.
Open iTunes application on your computer. iTunes will ask you to update or restore your iPhone. Try Update first. If that didn't work, then repeat the steps again and this time click Restore.
Remember, it may take a while to restore the iPhone (the iOS firmware has to be downloaded, you will see the Download button - a downward arrow button with spinning circle around it, at the top right corner of iTunes screen. Click it to see the time remaining)
Please let me know if that didn't work, so I will continue to help you until we fix the problem.
If the above doesn't work, please don't rate me bad or poor or OK. Instead please let me know and I will try my best to help you to fix the problem
My name is ***** ***** I will be your device technician for the day.