That Aurum website looks like some sort of unfinished scam. Even when switched (from default Russian) to English. No real company registration information, no terms, no privacy policy (the usual red flags), GoogleMaps in dev-mode, SEO test texts all over the place. I know they apparently actually sell the modifications, but still...
And quoting the MacRumors guy in the video "I expected custom watch faces"... I thought you guys knew enough about watchOS to know that that's not possible for 3rd parties...