One of the items will be the initial one spawned/rerolled, while the other four will be from the item pool of the room the item is in.
Items spawned from chests normally have a small delay between when they spawn and when Isaac can pick them up; if Isaac has Glitched Crown, this delay is removed and he can pick up the item the moment it spawns, effectively forcing him to get a random item.
Chests have to be lightly tapped and immediately walked away from to avoid accidentally picking up the item so Glitched Crown can be used properly.
If obtained during the Genesis item sequence, the effect will start on the second item after grabbing Glitched Crown.
Items seen as options count the same way as items normally seen. This essentially depletes item pools at 5x rate.
A good strategy to get the item you want is to remember the one that becomes before it in the cycle. Stand as close to the pedestal as you can and when you see the item that comes before the desired item move towards the pedestal.
Binge Eater: adds a random food item to the cycle, for a total of 6 items on the cycling pedestal. Only the pedestals generated after picking up Binge Eater will be affected.
The Glitched Crown is a nod to a visual glitch in Super Mario Bros. where if the player has more than 99 lives, often achieved by the Koopa shell infinite 1up trick, the lives counter shown at the start of each stage shows a crown.
There are five question marks in the item description, a nod to the five options that the item gives.
The crown's glitched appearance looks to be a sprite error, a bug that messes with video game sprites by making their sprites either devolve into unintelligible pixels like in the bottom right quarter of the crown, or renders the sprite incorrectly, like the flipped effect of the top right quarter of the sprite.