What galaxies are those? From what I have seen the oldest galaxy observed by Webb was formed some 700 million years after the big bang, certainly able to be within the 13.8b year old origin of the universe.
The graphics depict a slice of a 3 dimensional view on a 2 dimensional surface. The explosion did indeed evolve in an omnidirectional patter from the origin. It similar to the demonstration of a weight on a trampoline showing the curvature of spacetime. That is also only a small 2D slice of a 3D system.
Neal