I'm not entirely sure how broad this job restriction is. Say for a coffee shop, does it mean you can't be a barista? Or a wine sommelier? It is working in a "shop". Is it that a foreigner can't do anything in the front of the shop in any way, even when it's a specific position that requires certain skills?

In this case the "shop" is qualified as restaurant.

You are OK as barista or sommelier.

What you can not do is the give them the bill and receive payment, you'll need a Thai for that.

Shop attendance is like working in 7-11

Translating literally from the Thai item 6 in the law is, "Selling things in front of a shop." Most baristas sell things as well as make coffee, so they are probably not OK, if they take orders and cash, in which case there is not much point in having them.

A qualified sommelier is not a restricted job...