Persona follows the LIFD architecture: http://www.open-mike.org/entry/lifding-the-web

Popups allow us to create a nice messaging channel between the shim / localstorage at persona.org and the website the user is trying to log into, without losing their state on that website.

> 2. Are developers permitted to strip the Persona branding - to make the login process seem to flow with the current website - not a bolt on?

Sure. Brand it however you want. "Sign in with your email" converts best. The popup will always follow the same basic form, but you are able to add your logo, a human readable name, and a background color to influence its design: http://identity.mozilla.com/post/55796551587/persona-a-login...

Check out the login on https://see.drupalpersona.me https://webmaker.org and https://ting.com for examples.

> 3. Would you consider including tiny profile icon links next to the button itself, to facilitate single-click profile sign-on/switch?

Our UX folks are actively experimenting with this. Look for Ryan Feeley's posts on the dev-identity mailing list for some explorations.