He's not just shutting it down for an extra 4 days. There is a huge difference between a recess and a prorogation. During a recess (which is normal for conference season) all normal functions of government continue, including select committees and the house of lords etc - all the elements that hold a government to account.
This is different - this is a shut down of all departments, which for this length of time given there are no elections or holidays is being done purely to remove the government of parliamentary scrutiny.
Whichever way you dress this up it is dangerous, reckless and flies in the face of parliamentary sovereignty which we should all hold dear. It sets a potentially very unwelcome precedent.
https://www.channel4.com/news/factch...tion-explained