Our design creates a visual pattern from combinations of up to 172 spots of light

The article goes on to state that the trial used 10 of these. So I guess the quality would work equivalently to a 40x40 pixel resolution or something.

Another guess waiting for authoritative source: it could possibly be applied when talking about the quality of a braille pattern (assuming that's something one does) :)

Also, it's a word with a definition in the dictionary and I'm sure plenty of blind people are curious about words :)

I’m not blind and don’t personally know any blind people but I can imagine that blind people have heard of television at this point and the more curious among them have familiarized themselves with the technical implementation. Therefore a blind person understanding what resolution means shouldn’t necessarily be surprising.