Ran some tests - This behaviour happens whether I copy the bitmap image to the clipboard or not.
However it does not happen if I use the menu to capture the screenshot but only when my hotkey of Ctrl-Shift 2 or the default shift-printscreen to capture a specific region triggers the notification.
The shortcuts for printscreen for current monitor,  ctrl-prtscreen for everything, Alt-printscreen for window do not trigger it the notification popup.

Notifications on my phone already show up on the computer but for whatever reason this selected region (which i use ALL the time) triggers this notification.

The Flow software is an awesome experience, allowing you to use the same mouse, seamlessly between multiple computers (up to 3) and can copy & paste text, images, and files between them, providing they are all on the same network. It also can copy & paste between a Windows PC and a Mac. That one feature, alone, makes this mouse worth it.

-app103 (February 10, 2019, 05:53 AM)

Microsoft have 'mouse without borders' which does the same thing. It's a more user friendly version of synergy.
One thing to be aware of, if you are actually connected to the computer that is at the other end of the house and then you have moved control to the computer you are actually sitting at, the mouse is very very very sluggish. It took me a whole day to work that one out once!