A beacon signal including image information and an application to cause acknowledgment of receipt of the beacon signal is transmitted in order to measure approximate latency in transmission over a communication link that exhibits latency such as a packet switched digital network. Transmission latency for image information for an image included in a web conference is then estimated and elapsed time after transmission of such image information is measured and an indication provided to a presenter or conference monitor when the image should be visible to a conference participant which can be easily selected by the presenter.