The Davos effect refers to when two high status people walk towards each other with no idea who is higher or should get out of the other's way.
It happens in environments where there are very high status people but with no hierarchical context or idea of who the others are.
The term was coined for the World Economic Forum (WEF), held in Davos. Because high status attendees are not allowed to bring an entourage, no one knows who is higher in status and they habitually walk into each other because everyone refuses to give way.
Those two CEOs just showed the Davos Effect, they walked directly into each other, neither knew who should get out of the other's way!