Mitigation Blocks are reversal of Order Blocks.
"Breakers" are specific Mitigation Blocks that were used to run Stops. They're specific, short-term Orders placed specifically for a Judas swing or Stop Run.
See my attachment for what I would normally qualify as the breaker in that situation. However, you do point out a run back to a Mitigation block, that's double stacked. Note how much that big Bullish OB during LO is worked back in before it's reversed. After breaking the Low, it popped back up real fast to the wicks of that bigger +OB within LO to unwind what they could before taking off for +90.