very similar but the denons do not look like the same exact can. The yamahas and sony have square piece where head band meets, the Denon is oval, and I dont see the 3 air vents either. I'm not saying they might not still all be rebranded OEM, but it is not the same exact phone going by the picture.
In addition to the grille lines across the middle the 5ma's have 3 air vents, located along the top edge, they would be above where the letters "Denon" are on the headphones in your picture. I could'nt tell from your pic if they are there or not.