It's a common test to ensure you're truly comfortable with your decisions and actions: If a major newspaper would describe your actions or quote you directly on their front page tomorrow, would you still stand behind those words and actions?
The "test" is much older than Stripe but we often use it as a shorthand to ask ourselves whether we truly think a certain course of action is the right one.
If you read about X on the front page (in potentially a negative light) would you feel good about it, could you stand behind it. This helps with clients who are considering going sideways. Usually their lawyer will make some long complex argument about why something is "OK" or "legal".
We might disagree technically as well (ie, no its not legal), but sometimes it is easier to ask, hey, if this were on the front page tomorrow, would you feel good about this? The reality is the board members or whoever who have a lot of reputation really would NOT be OK with whatever - and usually speak up at this point, particularly as their personal upside to doing whatever bogus BS is low and their downsides are often much higher.
The "test" is much older than Stripe but we often use it as a shorthand to ask ourselves whether we truly think a certain course of action is the right one.