Why is my phone downloading something while turned off?

[AC Question]

I recently updated my S6 and everything has been running smoothly. I turned it off and started charging it. When I looked back the screen was blue and a downloading file icon is in the center and it reads "Downloading... do not turn off target". In the upper left hand corner of the screen in small print it says Factory mode and other details like product name and status. What is happening and will my phone start again?

 

[Almeuit]

Your phone should be fine. Try booting it up.

 

[B. Diddy]

Welcome to Android Central! Download Mode (aka Odin Mode) is used to copy a firmware file from your computer when connected via USB, and usually requires you to press Power, Home, and Volume Down at the same time to boot into. If you're not connected and not actively transferring a firmware file, you can safely power the phone down. If you don't see any option to power off or reboot, then press and hold Power and Vol Down together for about 15 seconds to force a shutdown. Then power on normally again. Does the same screen come on again?