A door to a secret Antarctic base? Here's what this image really shows

Pareidolia is a myth

Here, more "doors", not far from the main entrance pinned.  

Very pretty ice.

  All that is covered in the video.

I like more a 'door' on Mars. https://explorersweb.com/natural-wonders-dog-door-on-mars/

Also naturally occurring, but it certainly looks cool.

Pareidolia is indeed quite real. Look it up. Here is one site that explains it: https://www.livescience.com/25448-pareidolia.html The remainder of the research is up to you now.

I wonder what that pic looks like without all that snow. Seems like it's just an outer, on-site access door shell with a fabric covering for snow slides. That location looks ideal for storing normal facility hazardous waste or other general supplies, especially if it were originally a natural cave that was retro-fitted for that general purpose. The nearby flat area looks like lit may be for larger, excess facility non-hazardous open waste or pallet supplies. This in no way looks (to me) like a covert, obsured extrance to any informal facility, much less an inter-dimensional portal.

A door to Atlantis?

Come to think of it, Svalbard's 'Doomsday Vault' reminds me of this door to a secret Antarctic base. Except, there's no heavy snow fallen on Svalbard's Vault's door.