Revealing Characters Visually
Film and television are visual mediums, and even though dialogue is a large part of screenwriting, dialogue should enhance the visual story, never be used as a crutch where the dialogue is necessary to understand the story.
The following scene from Lethal Weapon (1987) is an excellent example of revealing a character visually without using dialogue. Instead, the environment and how the character interacts with objects in that environment illustrate his desires, both internal and external.
Lethal Weapon (1987) - "See You Later"
Detective Martin Riggs is a despondent, grieving widower. He's drunk, depressed, and suicidal, all self inflicted after the death of his wife. We learn this not from dialogue, but instead from how Riggs engages with various objects in his environment: the wedding picture, wedding ring, gun, bullet, liquor bottle, etc.
Even the TV playing Looney Tunes and Bugs Bunny yelling "Merry Christmas" enhances Riggss’ emotional state because it is much more heartbreaking that he is so isolated and hopeless during Christmas.
Riggs does say "See you later" at the end of the scene, but his line is not necessary for us to understand the complex emotional layers he is struggling to navigate. We learn everything visually.
As a screenwriter or filmmaker, you want scenes where characters are alone because when they are truly alone is when they will be most vulnerable and emotionally honest.