1. A method comprising: receiving, at a computing system, a first stream of video images corresponding to a videoconference; receiving, at the computing system, a second stream of video images corresponding to the videoconference that is different from the first stream of video images; accessing, by the computing system, metadata associated with the first stream of video images and specifying an upper alignment reference height and a lower alignment reference height within the video images of the first stream; based on the accessed metadata specifying the upper alignment reference height and the lower alignment reference height within the video images of the first stream, defining, by the computing system, a layout for concurrently displaying the first stream of video images and the second stream of video images at a location that substantially aligns a top edge of the video images of the second stream with the upper alignment reference height within the video images of the first stream and that substantially aligns a bottom edge of the video images of the second stream with the lower alignment reference height within the video images of the first stream.