They probably used this exposure when the lights had a lot less output. But a photo that's mostly dark wouldn't make a good review photo.
What exposure would be reasonable? After playing around with my camera, I think about 2 seconds at F4 and 100 ISO is about right.
I used the photos to compare different beam spreads and intensity. I don't know how far away the playset is, anyway.
For instance, the Dinotte 200L (200 lumens) I have this light, and the photo is probably overexposed compared to real life. But it's still a good bike light for low speeds, with a nice beam width with no sharp cutoff.
Compare it to the Dinotte XML-3