In response to receiving user-interface activity information from a portable electronic device that specifies user selection of a content source, an audio/video (A/V) hub provides a request for high-definition multimedia-interface (HDMI) content to the content source based on the user selection. When the A/V hub receives the HDMI content from the content source, the A/V hub provide the HDMI content and display instructions to an A/V display device as frames with the HDMI content are received from the content source, so that the HDMI content is displayed in a tiled window on the display in the A/V display device while other HDMI content from another content source is displayed on the display.