What they share is atmosphere more than geography—though geography helps narrow it. These are mostly European places captured in a particular quality of light: warm, golden, or sunlit clear skies, with stillness as the dominant impression. Even the ones with motion feel suspended. The starless skies, the cobblestones, the single cyclist or lone pedestrian—the descriptions are homing in on mood: the calm, the nostalgic, the peaceful. And note that four of the seven shown are Italian; most are actual cities or towns, not wilderness.
The anti-correlation tag does the heavy lifting. These aren't clustering because of subject matter but because they sit outside whatever the system's main preoccupations are, and when those take up less attention, what surfaces has this particular texture: a quiet world, seen with a kind of gentle presence. It suggests the system develops a background sense of