It may be a friendly greeting without which people would be insulted. It might be a sexual advance to a woman which will get the guy killed. It depends on how form interprets it. A kiss is an event. Events by themselves are meaningless.
Earthworms dig new tunnels.
Bridges collapse in the mountains. Viewing these things has no gripping or compelling interest for most people. A hundred scenes of men kissing other men's wives on the cheek with no reaction from the husband would not be interesting. A screenplay of any of these events would do poorly at the box office. Events must affect the substance of people's lives in order for us to take an interest.