It's not, because it appears the tail design is copyrighted by British Airways.
Well, it is, because it's China, and they don't care.
In all honesty though I think China Eastern has the worst livery ever. Not because it's objectively the ugliest, that probably goes to some rinky-dink regional carrier somewhere (maybe great lakes?). No, China Eastern's is the worst because they're a real airline who can actually afford things like brand strategists and graphic designers to create something nice. Instead, they created the most boring, lowest-effort livery possible and called it a day. At least ugliness is interesting, the true cardinal sin of bad design is making something boring.
China Eastern had a revenue in 2016 of $114 billion U.S. Dollars. They couldn't invest $5 into making something better than this?