I have a question... Why does this model show the 'Big Bang' as being mono-directional? The explosion of anything is far more random and omni-directional. That seems to me to present a problem...
Seems to me they wanted to emphasize time, which is unidirectional. The focus of the carton is the evolution of the universe through time. They attempted to represent the 3-d spatial expansion of the universe through time by graphically implying a third dimension, projected into and out of the two dimensional plane of the cartoon.