Who is Ica-Stig and why do the Swedes seem to care so much?

You might have noticed a lot of discussion about a supermarket advert in Sweden this week. Here's why it seems like the whole country is talking about Ica-Stig. https://www.thelocal.se/20210201/who-is-ica-stig-and-why-do-the-swedes-seem-to-care-so-much