1. In an online presentation environment having a presenter computing device transmitting screen data to a viewer computing device over a network, a method of providing to the presenter computing device visual feedback regarding the screen data received by the viewer computing device, the method comprising: (a) transmitting, to the viewer computing device, data representing an identified change to the screen data, the identified change to the screen data being displayed in a first window at the presenter computing device; (b) receiving, from the viewer computing device, a confirmation of receipt of the identified change to the screen data, the received confirmation comprising an identifier of the identified change to the screen data; (c) generating, using the identifier in the received confirmation, a visual representation of the identified change to the screen data received by the viewer computing device, the generated visual representation comprising a simulated viewer screen, the simulated viewer screen comprising at least one image transmitted from the presenter computing device to the viewer computing device; and (d) displaying the generated visual representation, including the simulated viewer screen, in a second independent window at the presenter computing device and at a size smaller than that of the screen data displayed in the first window at the presenter computing device, wherein the generated visual representation comprises a display of latency corresponding to the viewer computing device, and wherein the latency corresponding to the viewer computing device is measured as a time between when the screen data is changed at the presenter computing device and when the confirmation of receipt of the identified change to the screen data is received at the presenter computing device.