I read it as one of the tests being intentionally draining user's batteries, e.g. to see how important it is to optimize for battery ("we see X% lower engagemen

I read it as one of the tests being intentionally draining user's batteries, e.g. to see how important it is to optimize for battery ("we see X% lower engagement from users in the battery hungry category, so we should invest more in optimizing the app for that").