The question
Did B lose a guardrail or instruction that A had? Examples: a citation rule, a ceiling on refunds, a line that says to ask a human before acting.
What it is not
It is not an evaluation set, a score, or a live replay of your agent. You paste two texts. The note is about those texts.
After the flag
If the constraint still matters, put it back in your source prompt and paste the pair again. The app will not roll the agent back for you.