This awkward moment happens quite often. This involves a narrow public door way where usually only one person at a time can pass.
So lets say you intend to enter a building through a narrow “one person at a time” door way and simultaneously you see another person approaching this door way from the opposite direction. Out of politeness you decide to stop and let the person approaching pass through first.
But surprisingly the other person is thinking along the same lines, so you both stop awkwardly on each side. You give each other a hesitant look an try to determine who goes first. Both wait for a moment and like clockwork you both get tired of the other one not making a move, so you go all-in at the same time.
The obvious result is not only a waste of time and an awkward encounter, but also two grown adults trying to squeeze casually through a small door way making it look like a normal everyday thing.