Is that Vitalik sitting on the horse? 
That is what it seems like. But, as per suggestions given in their Telegram group, we have to focus on the Whitepaper. I suppose, Vitalik wont help us in this hunt. 
C'mon guys, that's not Vitalik sitting on the horse, horses don't have a horn... That's a Unicorn!
We can say is Vitalik sitting on the Unicorn holding a Unicorn... And the unicorn is Mining ETH on each step.
I only hope this puzzle isn't fake.
Vitalik is adventuring in a moonlit night, while his unicorn is mining ETH. CPD planet looks like Saturn and is in the sky.
This is how it appears to me. But, whitepaper does not say anything about mining.