Copywork is an exercise where writers just copy verbatim another writers work. If you haven’t done it, it is an extraordinary way to see how the greats work. It also tends to improve your own writing skills - at least as long as you are copying from your betters. This seems like the web design version of this.
Obligatory link to a relevant Jorge Luis Borges story: Pierre Menard, Author of the Quixote (about an author who copied Don Quixote word for word) https://raley.english.ucsb.edu/wp-content/Engl10/Pierre-Mena...
Edit: Which you might know well enough. Just wanted to add some more context.