Photo one shows a somewhat strange looking object.
Photo two- This is the object again-clearly a plant pot holder.
15 pots can be carried by hand to anywhere in the garden or put into a vehicle using the holder,( which stack when not in use).
On placing on the ground they are held securely, unlike any normal tray. The pegs give height and the side clips- stability.
These holders come in many sizes, and are cheap to purchase, and do not collect water like trays-( note that even each spike has a water release feature)- however one or more holders could be placed in a tray – 15 pots , a time ,for watering from below, and then lifted out to drain.
Such a simple idea- it works a treat . Saves countless hours !!!