It could cause a problem to the people who have to deliver the goods, as they are putting themselves at risk to do so. Similarly, it could harm the people packing the parcels in warehouses where it is impossible to observe the social distancing rules.
On the other hand, I'm pretty sure that one of the government spokespeople on the bulletins said that we should continue to order online to help the economy, and doing so is almost certainly safer than people going out to the shops.
It makes no difference that I can see if someone adds an inessential Easter egg or a bottle of bubble bath to their grocery order, as the risks are being taken anyway, but that is very different from someone ordering one of those things on its own from Amazon or eBay.