Black bar at the bottom of my screen on new MacBook 2016
Finaly after seeing this questionI understand what it is you are seeing.
It appears to be the touchbar zoom functionality.
You can find this and deactivate it by rightclicking the system preferences item.
Then select accessibility>zoom and deselect touchbar zoom.

Be sure to use the rightclick method to go to accessibility, otherwise the touchbar zoom option wont show up.