This couple ,were on our Railtour, and so followed us onto this Lake Steamer,out of Lucerne bound for Hergiswil, by a circuitous route ; essentially , a lap of Lake Lucerne , dropping us off by our hotel in Hergiswil.Imagine our surprise,then,when this shot appeared on the screen.Where did the image behind them come from.?They were on a bench with darkened glass behind it.