These are known from ancient times as the Celestial Golden and Silver Gates, respectively. Consider the images you see above, where these stargates are pictured as imprinted spheres surrounding the globe of the earth. It seems likely to me that it was from these stargate intersections of the two great celestial rings that the XO or cross circle symbolism was derived. The MOB and entrance of the antichrist beast will be made via stargate transiting spirit entering into this realm's matter. The intersection of space and time - the merging of two space-time domains to facilitate a transit, or to hijack-repurpose them both - the union of the X and O producing a flash of lightning from the Abyss to establish the throne of the goddess (OTO) - these concepts have become very familiar in recent months and years. The variegated instances of XO and the double X constructions seen on columns and doorways model stargates, as pillars themselves that flank gateways - and beyond mere modeling actually are stargates when designed and executed according to theurgical principle. These symbols, like the pentacle and hexagram are usually signs of potent ritual magick.
One example from film media is seen in the image below. It's a screen capture from a film titled, About Time. It stars Domnhall Gleeson as a time traveler (who starred as Caleb in Ex_Machina).
Note the XO pair flanking the space-time sanctuary's divide. There's actually 2 sets, framing the space where the action is. It's a wedding, of heaven and earth. Time traveler - being joined together with a regular earth woman named - Mary. Their lives are being crossed and merged in a union as through the stargates.
If you've been tracking with the blog in recent months you'll appreciate these two commercials. (Thanks, readers, for watching with us and sharing such items of interest!)
Jaguar XE - Unleashed
Guinness - Pure Genius commercial w/ Rutger Hauer