A method for controlling a display device, according to one embodiment of the present invention, comprises: displaying, on a main screen of a display device, content including at least one object; receiving an input for selecting a specific object from the at least one object displayed on the main screen; specifying the specific object by corresponding to the received selection input, expanding a specific area including the specific object; displaying a window including the content displayed on the main screen; displaying the expanded specific area on the main screen; and displaying, within the displayed window, an indicator for displaying the expended specific area, wherein the specific area changes according to a position of the specific object, and the content corresponds to a video.