Filmmakers often tell us how to react, the emotion we should be feeling. These feelings naturally mirror what the character(s) are experiencing.
One of the ways filmmakers do this is by what happens in the very next shot. For instance, if someone is in a scary scene, the next shot might contain a high-pitch sound, resembling a scream. It could be a train whistle, brakes grinding, etc., but it’s there to (at least subconsciously) tell us how the character is feeling.
Similarly, if something funny happens in a scene, the filmmaker will start the next scene with someone smiling, or a group of people laughing.
These cues give us a sense of depth, continuity, and authenticity. It just feels real.