Literary allusion: The White House at Dunsinane Hill

Excellent example of literary allusion:

Birnam Wood arrived early. pic.twitter.com/i3rQok6G6D

— Shakespeare Magazine (@UKShakespeare) 28. November 2018

"Birnam Wood arrived early" in Shakespeare Magazine's tweet refers to the prophecy made by the three witches in Macbeth. 

In Shakespeare's play Macbeth, Macbeth is told that he will only be defeated when Birnam Wood comes to Dunsinane Hill (where his castle is). Later, his enemy's army comes through Birnam Wood and each soldier cuts a large branch to hide himself, so that when the army moves on it looks as if the wood is moving. Macbeth is defeated and killed. (1)

The picture in the tweet shows this year's Christmas decorations at the White House (2018), with the First Lady, Melania Trump, admiring it.

Of course, the parallel drawn (indirectly) between President Trump and Macbeth is wildly exaggerated and utterly inappropriate. But the tweet above is not to be taken literally and is obviously intended as a tongue-in-cheek comment on the style of the decorations. ______________
(1) short description taken from ldoceonline - thank you.