The art of Disney on display, from sketches to models.
Adults will probably be more interested in the displays and art work in the Disney Gallery than kids will be, but it's still a great place to stop. We popped in here during the display of trains sometime around midnight on our way out of the park. I had 5 kids with me, ages 7-11 and they mostly enjoyed it. I think it gave them a good chance to see that everything at Disneyland is created by an artist and is incredibly beautiful and special.
A model of the Disneyland Railroad and Main Street was the biggest hit. Other diagrams of all the different trains around Disneyland were also interesting. We spent 5-10 minutes here and it was worth it.