Q: New Apple Watch Charging Cable Screen

Have you tried to force restart the Apple Watch? See:  https://help.apple.com/watch/#/apd521a8a902

Force Apple Watch to restart:  Hold down the side button and the Digital Crown at the same time for at least ten seconds, until the Apple logo appears.

Follow these directions to set up and pair the watch:  https://help.apple.com/watch/#/apdde4d6f98e

Contact Amazon. The battery of that watch probably has a problem. 16 hours is too long, even for the first charging.

I'd return the watch and ask for a replacement.

Have you checked if the watch has an activation lock?

https://www.icloud.com/activationlock/

Hi

When charging your watch, check that:

• All plastic wrap has been removed from both ends and both sides of the charging cable (check closely on the head of the charger).

• The back of your watch and the head of the charging cable are clean and dry (clean them with a nonabrasive, lint-free cloth).
• The charging head is properly aligned with the back of the watch, with the concave / curved side touching it fully:
  • Some watch docks, stands, cases or protectors might hinder this.
• You are using:
  • A genuine Apple Magnetic Charging Cable, or;
  • A genuine Apple Watch Magnetic Charging Dock with a genuine or Apple-certified Lightning to USB Cable, or;
  • An Apple-certified magnetic charging module.
  • If possible, test with another cable, dock or module that meets these requirements (for example, by borrowing a cable from a friend).
• If you are charging your watch by plugging into mains power:
  • Check that the USB connector on the Apple Magnetic Charging Cable is pushed fully into the USB Power Adapter.
  • Check that the USB Power Adapter is pushed fully into the power outlet.
  • Try using different adapters from the following:
    • The genuine Apple USB Power Adapter that was supplied with the watch, or;
    • An Apple 5W (iPhone) or 12W (iPad) USB Power Adapter, or;
    • An Apple-certified (MFi) third-party 5W USB power adapter.
  • Try using a different power outlet (one that is known to be working properly).
• If no other suitable power adapters are available, try instead charging via a USB port.
  • If charging via a USB port on a computer, ensure that you use a USB 2.0 or 3.0 port, the computer remains turned on and awake and the cable is plugged directly into the computer (not into, for example, an external keyboard).
• If your battery is very low, you may need to wait for a few minutes before the green lightning bolt appears (confirming that charging has started).

Under normal operation, charging should only take up to around 2.5 hours for a full charge.

More information:

Check your battery and charge your Apple Watch - Apple Support

If your Apple Watch won't charge or it won't turn on - Apple Support