It's all about convincing us that we have short-lived access to a special price, which in reality might not be true at all. Pushy patterns are designed into online shopping websites to encourage impulse purchases . For instance it can be a count down timer, a stock count or a "Buy Now!"-button on the website.
By removing friction from the buying process, pushy patterns reduce your mental load, but they also reduce your time for reconsidering your purchase.
With Black Friday fast approaching Carys' best advice is, "Simply pause". Pause and think about if you really need what you are about to buy.