If the player has an Egg in their Party, or in Bill's PC, when said PC is accessed, the player may notice some oddities. For one thing, when the Egg is picked up, it displays the level of which the Pokémon will hatch out (most likely will be level 1). An even stranger instance is when a Pokémon is swapped with the Egg: the Egg will produce the cry of whatever Pokémon it will hatch into (in this case, the cry of a Togepi).
Here's an image of the level displaying Egg, I cannot really prove the crying though.
Here's an image of the level displaying Egg, I cannot really prove the crying though.