[XCSme]

The idea is really cool, but implementation seems hard to get right.

Apart from the security issues mentioned by others (related to storing user auth/session data), what happens if there's an update to the website/application where the screenshot is being taken from? Or if they add an announcement banner at the top, all content will be displaced.

[joegahona]

I was thinking through similar scenarios. I think there will be tons of fringe cases that this won’t work well with, but for the core use cases (Google Analytics, Amplitude, etc.) it will work more predictably. An analytics tool should have minimal announcements, pop-ups, A/B tests, etc. This isn’t the right tool for perpetually updating screenshots of a specific region of CNN’s homepage.