Just winging it here...
The context is actions to address risks and opportunities. So for example, you may define a mitigation for a risk and then you may be able to demonstrate that the mitigations were able to enhance desirable effects. Conversely, opportunities may arise where you can achieve improvement. And I can think of cases where risks could drive improvements and opportunities could enhance desirable effects.
I can see a place for both, however a fine line there may be.
