An average image leaves you with the abstract features common to all the matches, which tells you far more about what the brain-traffic is up to than showing a single match. And being able to look at that is astonishing in its own right.

It's easy for laypeople to misinterpret things they don't fully understand, but I think they can be disabused of misunderstanding by careful explanation. And we can get from here to there without invoking slipperiness.