Swedish fintech startup iZettle raises €60M

In the Norwegian market, iZettle gave away (price under a euro) atm card readers that connect to iOS or android devices, with an app that made it easy to open a lemonade stall or the like. Adding new items to sell was great fun -- place espresso/bagel/muffin on table, take picture, decide on price, and there it was, in the "shop" on my phone.

Made me wonder about the steps from this shop instantiated locally on my iPhone to a shopify-like online presence. What are the hurdles to mirroring the local instance of the shop to something served at [yournamehere].mall.izettle.com ?