Highlighting the user, that is logged into the lobby with an arrow in the buddy column.
When he is listed in a game the arrow will point on that game, shown in the buddy column to.
Helpful when user got kicked off game due to disconnect.
He can easily find his game back where he was in.
Its sortable with buddy column, it show the user and the user's game first.
Here an example, where "fsvn" is logged into the lobby and has entered "ffffffff"'s game : http://imgur.com/a/FYUUx
(this is actual a double login, as u see, first i logged in with "fsvn" and then go to "ffffffff"'s game and then i take another window and logged in again as "fsvn" to demonstrate that im shown in that game (and in the lobby). Normaly i ("fsvn") would got disconnected from the game and then reconnect from the lobby to the game (and the arrow will show me the game).