That one has "kind of" point that it's optimized for use in digital printers (both inkjet and laser, which involves some compromises), at the expense of it not being optimal for writing with pencil. For a pencil, a tad rougher surface could be better.
But the headphones have no "optimization" of any kind for such D/A signal source. In case of batteries, this "digital" title sometimes means they are high-power cells because digital cameras were known to be power hungry. Unsurprisingly, before the digital camera era, camera batteries were sold, and expensive. Even back then, charging up the flash capacitor took quite some peak current, cameras were used outside so possibly at cold temperatures, and you didn't want the camera to die during use. So these "digital" brands may be higher current, more expensive cells, compared to ones sold to be used in remote controls for example.
But eventually, coming to 2010's, most digital cameras transitioned into rechargeable li-ion packs specific to the manufacturer. I haven't seen "digital" batteries in a while.