The animation is produced by the Winton Programme for the Public Understanding of Risk based in the Statistical Laboratory in the University of Cambridge. The aim of this Programme is to help improve the way that uncertainty and risk are discussed in society, and show how probability and statistics can be both useful and entertaining!
From a linked web site: Comparing and communicating small lethal risks is a tricky business, yet this is what many of us are faced with in our daily lives. Ideally we need a "friendly" unit of deadly risk. A suggestion made in the 1970s by Ronald Howard is the use of the micromort: a one-in-a-million chance of death. This is attractive as it generally means that we can translate small risks into whole numbers that can be immediately compared. For example, the risk of death from a general anaesthetic (not the accompanying operation), is quoted as 1 in 100,000, or 10 micromorts.