Disclosed herein are systems and methods that allow activation of, and intuitive interactions with, a companion-display mode for an electronic device. An example method includes: receiving an instruction to operate the first electronic device in a companion-display mode in which user interfaces generated by a second electronic device are displayed at the first electronic device. In response to receiving the instruction to operate in the companion-display mode, the method also includes: concurrently displaying, on the touch-sensitive display of the first electronic device: a user interface generated by the second electronic device; and a plurality of user interface objects, including a first user interface object associated with a first function of a plurality of functions for controlling the touch-sensitive display of the first electronic device while it is operating in the companion-display mode, and a second user interface object associated with a second function of the plurality of functions.