They really aren't independent, they're instrictly linked. Mark Drakeford has stopped non-essentially item sales in supermarket, in his words "to level the playing field", surely by that logic he would limit e-commerce as well. However he hasn't. There's also an assumption that everyone is online and has access to shopping that way, there's still 11% of Wales that doesn't have access to the internet. Back to the point I made earlier, demand in those types of items doesn't get pent-up, it just moves to another retailer and bought elsewhere, so doing this to level the playing field is just a token gesture by Drakeford to appease those stores he's closing, and those shops that are currently closed aren't going to see a surge of business because he's stopped supermarkets selling clothes.
It may not be essential in your eyes, but to some it could be, which is why I couldn't sit there and say what is essential in a supermarket or isn't, as we have a broad spectrum of peoples needs to address. On the point of supermarket clothing though, it's an essential to those in society who need access to affordable clothing, which is why I don't understand Drakeford's logic here.
I think it's fine for him to decide on sectors and stores for opening because there is a broad recognition that the motivation for doing so is to control infection rates. What he's doing now is telling stores that are open what elements of their business he thinks is acceptable to trade on in order to protect others businesses, which is going far beyond what the purpose of a his fire break is intended to do. Kettle's are deemed as non-essential by the way, its classed as homeware. He's also stopped the sales of books within supermarkets also.