Official 2021 Mirage release

[highwire]

Usually I pride myself with having a big vocabulary, but prochronism is a new one for me.

Mirage Forum's autocorrect really wants to make the word anachronism. Anyway, in laymen's terms I'm thinking Casio wrist-watch in a cowboy movie, or a take-out coffee cup in Game of Thrones.

Exactly, prochronism is a type of anachronism. Both prochronism and parachronism are types of anachronisms, the former being artifacts being placed in the past, and the latter being events or things being placed in the future- like Abraham Lincoln meeting Clint Eastwood in the year 2000 (or today).