I'm a bit late on this comment, but I saw this image on the JPL-NASA website the week this came out. The photo of this structure was taken across a ravine (see the small creek running across the middle of the photo) and it is about 200 meters from the rover. The building is the size of a two story house and there appears to be several windows in it.
NASA HIDES THE SCALE of the images by showing close-up photos of gravel and rock at the beginning of the series, and then slips in the more distant images on the page for that day. There is never any distance or size comparision data given, like there was in the first rover mission, so the natural (intended) reaction is that everthing is "just a few inches tall".