Imagine flying all the way home after a week away, dumping your bags by the door, slumping down on your couch... and then realising you forgot to take a photo of Tower Bridge. You'd have to put your shoes back on, drive back to the airport, get back on the plane, fly back to London, get the tube into town, the bus back to the bridge and take your photo because you can't go into work on Monday morning without one. You'd be showing off all your London photos and they'd be going, Where's Tower...