The Xap menu has a Preview function. The Tools menu has a Detach Live Xap function. What's the difference, other than the Preview opens a new tab and the Detach opens a new window? Also, those words don't say something different to me, if they do actually do something different.
The difference of looking at the detached live Xap versus the Xap preview is that the live Xap updates in real time where the preview requires being refreshed to show updated changes. Is that helpful? How might that be more clear for you?
The difference in use-case isn't clear to me. I guess someone might want to share a preview in a particular state that won't change, while meanwhile making other updates to the Xap. In that case, maybe call preview "Shareable Preview" or "Preview to Share" and in the box on the right of the dropdown menu, explain that it's a preview that doesn't update.
If you share hte preview or the live xap, can someone who doesn't have a city login see one or the other or both?
The detached live Xap and preview are both limited to the Xap builder, so they both achieve nearly the same purpose in slightly different ways. It may not be worth having two features that are so similar, though the dev team may be able to shed more light on why there is a distinction. The only way to share a link to a running Xap is to share the published version, which is different from what's happening in the studio.