(I work at Stripe)

The end consumer will have a seamless experience between paying online and offline -- think buy things online, return in-store (or vice-versa). Your customers can initiate a subscription in-store that continues online with Stripe Billing. You will have all your reporting -- for both online and in-person transactions -- within the Stripe Dashboard. In terms of customization, we think our new SDKs will make it really easy for you to build the right checkout experience for your business. Also, you’ll be able to customize some aspects of the reader display (e.g., logos, color theme, splash screen, etc.).

R.E. "unified experience", this slots so cleanly into Stripe's stable of products: all of your reporting would be available in Sigma, all of your fraud data available in Radar, and with a little magic in the SDK side, all of your customer data available (unified) in Stripe's database.

Imagine if you're running a web store, and you want to go to a conference or convention or something and start selling your stuff there. All of your tools still work, all of your reporting still works, and crucially your accounting flow remains identical.

The customisation options are probably up in the air right now - I imagine developers won't get the ability to customise the UI available on the PIN pad in the first release, but I imagine that's where they want to get to.