Is 'Open Box' on eBay just amazon returns?

[KatyMac]

Twice now I have bought something on eBay and its arrived in amazon packaging

What do you think?

Bought a toy from Jaques on eBay and it was fulfilled by Amazon. DD says it’s quite usual.

It's annoying if you are making a conscious decision to avoid Amazon (and its more expensive on eBay)

It's called drop shipping, and money can be made from doing it.
It's where a seller is advertising something on eBay, but doesn't actually have the item, nor do they ever see it. They then order the item for you at a cheaper price from another manufacturer, the manufacturer then ships the item directly to you. The eBay seller then makes a profit from you.
People have drop shipping businesses and can make lots & lots of money from profit.