Viewing full screen applications in a sharing session

An attendee device in an online conference session views a shared application window in a full screen mode. The attendee device receives data for content being shared by a host device, including at least one application window at a first resolution. The attendee device receives an input to enter a full screen mode for one of the application windows and determines whether displaying that application window at a second resolution for the full screen mode requires the image data to be magnified. When displaying the application window at the second resolution requires magnified image data, the attendee device requests the magnified image data from the meeting server facilitating the conference session. The meeting server provides the magnified image data to the attendee device, and the attendee device displays the application window in full screen mode using the magnified image data.