That's sort of the point; you can't actually get it unless you sign up for that stock image service. It looks like it's free.
When I visited the site on a desktop browser, a thumbnail of the wallpaper was visible behind a gray tint which was behind a sign up form. It's some Adobe thing, so it's probably not spam or a deception service.
[doublepost=1484671689][/doublepost]
Alright, a bit more digging—including the use of developer tools to remove the gray tint (shown below)—has lead me to this—a 14mb, 8000x4000px version. Utter glory.