Remember that you are the witness to the children's spiritual emergence through the arts. You are modeling for the children how to speak about the arts responses that are created in the classroom. It is not your job to interpret or comment or judge their response to the activity. A few guidelines can help you create a quiet non-judgmental atmosphere in your class.
Tell me about your work is a basic response. Don't talk about what they have made but how they felt making it, how they approached it (fast or slow, many colors or few, lots of movement or just one repeating motion). Don't try to legislate what you see as the meaning in their work, and do not force sharing, but invite it. Let each child speak about their own work as they are ready to. You can ask them to share how it made them feel to move that way or what they thought about as they worked, or how they chose certain colors or words. These comments are not on the quality of the work produced but on the quality of the process as they experienced it. This focus on process is what makes the class different from a lesson on art techniques and moves it into an experience of the inner spiritual life.
The older the child, the more likely it is that they already accept art as product and ideas about talent. You must assure these older children that the activity is about noticing how they do things, and how they feel as they create rather than the final product. The more you model this kind of talk the more meaningful the sharing will be.
There are several ways to help children to respond appropriately to their classmates' work. One is to insist that any comments must be positive and to model that as the teacher. In other words, the children should choose at least one specific thing that they liked or noticed about the art or writing or dance. This kind of attention creates supportive rather than critical sharing. Remember that these comments should not be interpretations but I liked the way you did the colors or I liked the movement you made for anger.
Another way to reflect is to have the children place their work in the center of a circle and walk around looking at each response without comment. This approach works especially well when you are going to combine the responses, as the children see all the pieces separately first. Then lay down a larger piece of paper or a large mat and ask the children to combine their pieces in silence. They may have to move their pieces several times, but they may only move their own piece. After the pieces are set, invite comments about how the process felt. Was it easier for them to do this without speaking? Were they surprised by anything? Have them walk around the finished combination to take it all in.
Don't expect great revelations from children but be in awe of them when they happen. You may not hear immediate feedback from some children because they need more time to process their experience.