The Contemporary Resort’s signature restaurant, the California Grill, has started offering a Sunday-only brunch period called "Brunch at the Top". Offering spectacular views of the Magic Kingdom and surrounding Seven Seas Lagoon (even by day), the location does seem to offer a more relaxing experience than the evening dining period.
The brunch format is technically part buffet and part a la carte (plated) selections, the term "buffet" is not exactly correct. Small portions of seasonally fresh items, including sushi, are made and presented at the counter of the restaurants open kitchen, where guests can peruse and select anything that is available. You are free to roam up to that area, as often as you wish during the brunch.
In addition to the complimentary mimosas, there is an open bar (for an additional fee) hand crafting cocktails, beer, and wine selections. Included in the fixed price of the brunch are charcuterie, sushi, salads, a single selection of a brunch entree and a small dessert plate.