There's a link right there that goes to the official Nat Geo Tumblr account. Even if you choose not to believe their citation it was posted in 2014 before anyone had access to the AI tools that could generate this.
Also, Molly (account owner) mostly posts items from her own collection, and what isn't from her collection is researched and credited. I'm not saying it's impossible she'd post AI, just that it's unlikely.
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