Postcards from touristy places always show monuments without people just like they would be when they were built.
Postcards are taken at times where no people are in the monuments or with extremely long exposures in order to not catch the movements of the people.
Tourism is really present in all those places so postcards should allow people to be in it.
I am really fascinated with different movements or things we say when we take photos in front of a monument and by the fact itself that we are taking a photo in front of it. Like if we would need an actual proof of our body being in that place or if not people would not believe us.
In a place I visited some spots on the floor would tell people which is the best place where to take a photo of the building so that probably everyone has the exact same photo.
In some photos the monument itself is partially not being portrayed.