So, um, wut? Any ideas? (Other than maybe, I dunno, Google street view filling in missed shots? Google's streetview shot of our house consists almost entirely of sunlight glare in the camera lens.)
eta: Paul said "real estate" thinking "real estate scam" and I realised it probably was real-estate related: it was someone looking for comparables. There are a couple of houses for sale near ours, including one that had an open-house last weekend. So I suspect they got an offer and now are going through appraisal.