When East player (the only player with 14 tiles) has Mah Jongg after the Charleston, it is called an "Earthly Hand." If this occurs, it is considered a self-picked mah jongg and the winner is paid double by all players.
One might think that a player's turn begins when the previous player discards a tile but that is not the case. The reason for this is that turns can be interrupted when another player claims the discard to make an exposure. Therefore, a player's turn officially begins when they either pick a tile from the wall or call a discard.