A display apparatus includes a communication interface configured to communicate with another display apparatus, a display configured to display contents being shared with the other display apparatus and a video call user interface (UI) for a video call with a user of the other display apparatus, and a processor, in response to at least one of a gesture and a voice of the user included in video call data received from the other display apparatus satisfying a predetermined condition, configured to control the display to change a size of the video call UI displayed on the display.