Marks on mattress cover, as shown in photos. This is a mattress made from natural materials, so someone may want to have it for the coconut coir, wool or natural latex within it. Or a pet bed.
https://thelittlegreensheep.co.uk/collections/cot-cot-bed-mattresses/produc...
Green sheep Cot Mattress (Strawberry Hill TW1)
This offer has been gifted to someone and is no longer available.