Dinner isn't considered a character meal because there is no table-to-table character greetings during the meal. Fairy Godmother acts as a mistress of ceremonies, and she and the mice do a little show as aladams2 said, but they don't come to each table for a photo op and meet-and-greet.
Breakfast and lunch are completely different than the above. Four princesses in the dining room, each going to each table for the photo op and meet-and-greet, and there's something special when our little princesses get face time with the Disney princesses.
But all 3 meals have Cindy in the entrance lobby, doing a meet-and-greet and professional photo op with each party (behind velvet ropes, etc.) before they are escorted upstairs to the dining room. Cindy never goes upstairs to the dining room.