A flying car would be nearly magical for someone from 1880.
But a smartphone to someone from 1950? It would seem pretty fancy, but not impossible to imagine. The guy from 1950 already knows the basic tech behind it - it has a screen, it uses wireless data, and is powered by computers.
I think you have that backwards. A century ago people imagined flying cars but not smartphones. (See Albert Robida.)
Now, we would find flying cars "nearly magical" (myself included, having been recently amazed by modern vertical takeoff fighter jets) but apparently aren't impressed by smartphones (myself not included, even before having recently learned about semiconductor fabrication techniques).
But a smartphone to someone from 1950? It would seem pretty fancy, but not impossible to imagine. The guy from 1950 already knows the basic tech behind it - it has a screen, it uses wireless data, and is powered by computers.