Whether it's Jack Nicholson in The Departed or Tom Cruise and Penelope Cruz in Vanilla Sky, the preponderance of movie characters who are somehow great at drawing is infuriating. I can barely manage stick figures and these people are budding Al Hirschfelds.
The camera always goes out of its way to show the perfectly-executed sketch, as if it's art break time. Why? It's obviously not that the millionaire actors themselves are good at drawing and asked the director to include their work (which would be even harder to take). Instead, it's often a form of convenient story-telling, instant character development, and because everyone is just better at everything in movies.
One can't help but notice the pattern: Nicholson draws sharp political art in The Departed, Russell Crowe beautifully sketches birds in 3:10 to Yuma, and in Vanilla Sky Cruise and Cruz draw magazine-level sketches of each other on their first date, like we all do. Leo courts with gallery-level nudes in Titanic, the not-bad robot in I, Robot sketches a fine landscape, and Peter Parker in the 2002 Spiderman could easily get work drawing Spiderman, let alone photographing him. Even the multiple sketched penises in Superbad are really well-done. They put mine to shame.
Part of the reason is it's all quick, ready-made poignancy, a way to illustrate that there's more to the character than the writing has time for, like when the camera shows what books they're reading. Look this homicidal killer villain guy can draw and reads Proust! Maybe he's not so bad after all. Look this rom-com puppy dog drew a nice picture of the girl he's stalking, so she should totally go out with him.
A brief 10-second shot of a nice drawing the director's cousin made adds a sensitive dimension to the character that normally would’ve required multiple scenes of character building, scenes in which the camera shows instead of telling. Do you know how hard those are to write? A picture isn't just worth 1000 words, it's worth several pages in a script.
Granted, many of the films mentioned above are good, and feature plenty of respectable character development to go along with the drawing device. But whether in movies or life, talent’s often emphasized in an effort to rationalize their flaws, and add nuance to black and white characterizations of good and evil. We give a person the benefit of the doubt if they can do something, like draw or paint or sing (not juggle).
The same hardships which spawned their flaws and bad choices can also lead to an artistic ability. And so the drawing doesn’t simply suggest the inner life of a character, but often foreshadows the possibility that they’ll do the right thing in the end (or at least that they know better). Might as well skip the middleman and just close the movie with the protagonist and antagonist having a draw-off.
While these shots of perfect drawings are quick injections of depth, they may be there for the simple reason that everyone is just better at everything in movies. Most people outside of movies aren't that good-looking, don't have apartments that nice, and rarely say the perfect thing at the perfect moment. Why should the drawings be any different?
Movie characters are great musicians, painters, dancers... and they can beat anyone up if necessary. So if they draw you're damn right it's going to be at the professional level. It's going to be a drawing so good that you wonder: Why doesn't this character just solve their problems by becoming a professional artist? They're clearly talented enough.
All of the above is much easier to accept than the possibility that everyone else in the world is just way better at drawing than I am. Are the amount of characters who can draw well in movies commensurate with the amount of people who can draw in life? Perhaps. That would also mean—as previously mentioned—that they have more depth of character than I do. This is looking more and more to be true.
In any case, seeing a character do an out-of-character good drawing comes off as a sophisticated version of the 555 phone number appearing on screen—it's all just a friendly reminder that you're watching a movie.