If the box is empty, it picks up items and pickups in a room and stores them.
Moving Box can carry up to 10 items or pickups at once, randomly picked (i.e. items are not prioritized).
If the box is not empty, places all stored items and pickups in the current room.
Notes
There is no limit to the number of items and pickups that can be held in the box.
The best way to utilize Moving Box is often to absorb a large number of weaker items, then place them all into one room, and use a reroll effect to reroll them all at the same time. This is especially effective in Secret Rooms.
Any stored items and pickups unpacked from Moving Box will remain identical to what was originally packed; pills, cards, and runes will stay the same, Sticky Nickels will remain stuck to the floor, active items keep their charge in the box, and Chests will have the same contents as they would if they had been opened immediately.
Stealing from Shops and Devil Rooms is not possible; only items on pedestals will be packed up.
All existing Moving Boxes share their opened/closed state. Therefore, it is not possible to carry a Moving Box that is holding items within another Moving Box as the items must be unpacked first.
If used in a room with a choice of multiple item pedestals, only one of the choice objects will be packed up and the rest will remain and behave normally / the rest will disappear.
Book of Virtues: Spawns a box wisp on the middle ring. Moving Box must drop a pickup/item in order for it to spawn wisps. The wisps invoke the effect of The Book of Sin when destroyed.
Glowing Hourglass: If a charged Glowing Hourglass is stored in the Moving Box, it can be unpacked and used, refunding charges to both items to Moving Box only, while rewinding time and essentially allowing unlimited use can only be done 3 times.
Interactions
The D6/Shop Restock Machine/any reroll effect: Bad items can be collected over the run with Moving Box, then placed into a single room and rerolled. Extremely powerful items can be acquired this way if this is done in a Secret Room or Angel Room.
Car Battery: Activation swaps the contents of the box with the contents of the room.
No effect.
Death Certificate: Takes one random item from a Death Certificate room which is treated as if it was picked up causing all other items in the room to disappear and forcing Isaac to leave the area.
Flip: Moving items that are able to be swapped by Flip will still be able to be swapped after placing them down again. However, empty item pedestals that only contain the "ghostly" item cannot be moved unless flipped.
Options?: Only one of the choice pickups will be packed up and the other will disappear.
Void: This item's effect cannot be absorbed by Void. It will be treated as a passive item by the Void.
Box.
Moving Box can carry up to 10 items or pickups at once, randomly picked (i.e. items are not prioritized).
There is no limit to the number of items and pickups that can be held in the box.
Sticky Nickels will remain stuck to the floor, active items keep their charge in the box, and 
Chests will have the same contents as they would if they had been opened immediately.
Shops and 
Devil Rooms is not possible; only items on pedestals will be packed up.
There's Options and 
More Options can be taken.
The Polaroid and 
The Negative can be taken.
Boss Rush room, one of the objects is packed up but the rush is not started. The remaining item choices start the rush as normal.
Challenge Room or 
Boss Challenge Room the objects within can be packed up without starting the challenge.
Tainted Magdalene / 
Soul of Magdalene or 
Tainted Keeper can't be packed into Moving Box.
Book of Virtues: Spawns a box wisp on the middle ring. Moving Box must drop a pickup/item in order for it to spawn wisps. The wisps invoke the effect of 
The Book of Sin when destroyed.
Glowing Hourglass: If a charged Glowing Hourglass is stored in the Moving Box, it can be unpacked and used, refunding charges to both items 
The D6/
Shop Restock Machine/any reroll effect: Bad items can be collected over the run with Moving Box, then placed into a single room and rerolled. Extremely powerful items can be acquired this way if this is done in a 
Secret Room or 
Angel Room.
Car Battery: Activation swaps the contents of the box with the contents of the room.
Death Certificate: Takes one random item from a Death Certificate room which is treated as if it was picked up causing all other items in the room to disappear and forcing Isaac to leave the area.
Flip: Moving items that are able to be swapped by Flip will still be able to be swapped after placing them down again. However, empty item pedestals that only contain the "ghostly" item cannot be moved unless flipped.
Options?: Only one of the choice pickups will be packed up and the other will disappear.
Void: This item's effect cannot be absorbed by Void. It will be treated as a passive item by the Void.
The Binding of Isaac: Rebirth
