Mixed nuts, delicious. Mixed metaphors, confusing.
Take this statement from the Association of Credit and Collection Professionals’ Adam Peterman, quoted on CNN, defending bill collectors against charges of harassment, for example:
A bad apple can spoil the bunch too often, so we have to keep pushing that rock up the hill to help prevent that.
Somehow, mid-sentence, his bad apple turned into a rock.
And of course, the proverb Peterman mangles in the beginning of his confused sentence is “one bad apple spoils the barrel.” Last time I checked, bananas came in bunches, not apples.
Such sloppy communication is a sign of sloppy thinking.