The modern concept of using glass as cladding or facade for buildings allows us to see into them to varying degrees depending on a range of factors including the direction of light, its intensity, the degree of reflectivity of the glass used, whether it is tinted or not, and the differential levels of ambient light inside and outside. And then there are additional levels of complexity created by glass acting as a giant mirror reflecting and distorting the surrounding environment.
Sometimes the views are clear, sometimes they are subtle. Sometimes they are easy to interpret and sometimes they puzzle us. One thing is for sure, the built world would be a less interesting place if so-called flat glass had not been invented.