It depends much on the definition of an Easter Egg. People sometimes use it to say they have found a reference to another game, a movie, etc.. Or it can be just any unusual item that does not quite fit into the game or it is an item that stands out for other reasons. To me does it mean just something that stands out and does not necessarily have to be a reference to anything. I know of one or two games which had tons of Easter Eggs in them (i.e. Sacred, a very trashy RPG) where these were all outside references, so many, that it was too much and it began to svck hard.
In Skyrim I found things like the following:
- There are those butterflies in jars, which stand out.
- I also found several treasures that could not be reached by normal means, but one has to use jumping, climbing and/or
Whirlwind shout to get to them. Like the tower outside Tovald's Cave (far east) holds a treasure chest on its roof.
- Inside Labyrinthian is a skeleton, buried under water by a pile of rocks with one hand reaching to a ring. I so far have not figured out how to pick up the ring and it appears to be impossible. You might end up dying/drowning while trying to pick up the ring, just much like its former owner... Feels like a terrible joke on the players!

- And there is a path leading to Morrowind and a special site with a book (or journal?) in memory of those who came from Morrowind.