DY: He’s saying that his understanding of the psak is that the only permissible use of the internet is for business purposes, and not for any personal or recreational purposes. And the only place allowed for it be accessed from, is a place of business.
And he is asking how then can Mostly Music have any online presence, even outside Facebook (based upon their statement you quoted above of them following the gedolim), when their customer base who accesses Mostly Music’s website and purchases their music online are doing so for non-business purposes, but rather for recreational purposes. Thus Mostly Music is still enabling and promoting non-business use of the internet by maintaining their e-commerce website.