It's beautiful, but how does the user verify that the credit card popup form is being posted to a valid, secure site?

I mean, normally you'd first be redirected to a trusted payment site and verify its SSL identity in the browser URL bar. Then you'd know that the trusted site will do things properly from there.

But in this case, are you just supposed to trust blindly that the Stripe-looking payment form popping up on some semi-random site will really be submitted to Stripe? Am I missing something?