It could also be that someone just drove by that likes some feature of
your house or yard and wanted to photograph it. I also considered
that your property appraiser's office is updating their files, though
that is unlikely if yours was the only home photographed.
Try to get a good night's sleep tonight, and leave plenty of time
ahead of your appointment in case you have traffic problems. Be sure
you have your DL SS card, and anything else you were told to bring, at
the door, ready to go.
Good luck to you!! :)