Interestingly--at least to me--the description of how to make it, below, doesn't match the pictures on Flickr. I think that's because, as that site explains, the pictures are actually of Charlotte royale rather than Charlotte russe (which is described below and doesn't seem like it would look like brains).
No idea, but the front page has some interesting images from Flickr. One of which led me to this site, upon which all charlotte desserts look like brains, but which also contains some more historical information about this type of dessert.
I have to make this someday. It sounds teh alsome.
"Charlotte russe was one of the most impressive desserts that could have been served at the time and was mentioned frequently in accounts of dinner and dessert parties during the late nineteenth century. Catharine Beecher volunteered two different recipes for it, describing it as a combination of rich custard and tall sponge cake. One was to slice one inch from the bottom of the cake, turn it over onto its top in a mold and scoop out the insides, leaving one-inch walls. The cavity was then filled with the custard, the bottom slice replaced, adn the whole chilled. It could then be turned out on a cake plate and ornamented with frosting or candy sugar flowers."
—Susan Williams, Savory Suppers and Fashionable Feasts: Dining in Victorian America (New York: Pantheon Books, 1985), 115