Conversational search

Conversational search

Yesterday I was searching Peakto for images from Fukuyama, the Japanese city, and I noticed that when choosing "Conversational search", I got 383 results, all of them, except for one, unrelated to the city (and I don't have any photos of Francis Fukuyama).

As I understand, conversational search doesn't rely on metadata, but what then could the result be based on in this case?