Talking with your child about their art will help them process their feelings, but never force this discussion as it will lead to them feeling intimidated and perhaps will result in your child shutting down emotionally. Leave the choice up to your child when and if they would like to talk about their drawings or art pieces. Remember your child does not have that great of a vocabulary yet and this is why they prefer to talk to you via nonverbal means. You may also want to try using puppets when you are asking direct questions as your child will not feel as confronted. Also, reflecting on their art instead of asking direct questions will allow this process to go more smoothly. For instance perhaps use the following phrase such as: “I noticed you used that color” or “I wonder what this character in your picture is feeling”.
Although you can learn a lot about your child by looking at what they are saying through their art, don’t act hastily and over exaggerate your child’s expressions. The important thing is to listen unconditionally and keep your eyes and ears open to any clues your child is giving you. Many times this comes through repetition of drawing the same thing over and over. This is a good place to start!