This easter egg (of sorts) is shown between the ending credits of Resident Evil 4 and the Hunnigan transmission epilogue. It reads:
When reloading the Chicago Typewriter whiled in the Gangster costume, Leon will perform a special animation. If the player performs a few more reloads in quick succession, Leon will perform a different animation of him tossing and catching his hat.
If you walk up to Saddler's throne, it has a " ? ". If you click on it Leon will take a seat in the chair and rest his head upon his knuckles with his legs crossed for a few seconds.