Every great story involves a character who wants something, but many times in a film, just like in real life, our characters don't blurt out exactly what they want or say what they are thinking or feeling. Instead, characters use Subtext, which provides clues to something they feel or want, but they do not say directly. In filmmaking, using subtext gives the story more depth and keeps things interesting for the audience.
In the example above, Michel says "Hi!" in lights to get Amita's attention. But this gesture means more than just the word "Hi!" It means that Michel likes Amita.
If Michel directly said to Amita, "I like you" and she immediately responds to him, our story is over and it isn't very exciting. The subtext of his gesture is what gives this moment depth.