I would guess the picture on the eBay page is just the generic one they use for all DT-770s they sell.
As Beyerdynamic offers a 2 year warranty on headphones, I would think these refurbished ones would not be more then two years old.
As someone would not send to Beyerdynamic any broken headphones for warranty repair/replacement if more then two years old.
Might email them and ask what kind of warranty they offer with their refurb headphones.