Excellent idea. I think it would require someone with a good level of soft-skills so nobody on the team feels inadequate when their drawing is juxtaposed with the drawings of their colleagues, but I think if this ceremony were done right it could work great to strengthen social bonds and shared understanding. I’d love to try this.
Also: record it. These videos will be one the most precious resources in your team’s knowledge base.
I'd love to see a few examples of what's expected from such a discussion