It's true that cameras weren't going to be invented until the mid-1800s. But the 1500's did mark a period during which some artists started to take a different approach toward depicting people.
In the 1400's, most people who were having their portraits painted looked as if they had just come straight from the taxidermist.
Of course, this didn't apply to all 15th-century portraits,
especially if they were painted by Albrecht Durer.
But, let's face it, a lot of other 15th-century portraits looked positively posthumous.
But then we arrive at the 16th century. Check out this El Greco portrait.
To me, this woman looks ready to swoosh off the page and into the room. Or how about this one, a self-portrait by Artemisia Gentileschi?
I can hear the lute music, can't you? Or this guy, by Andrea del Sarto:
He's looking at me with extremely mixed feelings, as if to say: who are you and what exactly are you doing here?
But it wasn't just portraiture that changed. Pieter Bruegel the Elder (1525-1569) came up with the revolutionary idea of not just painting wealthy patrons and religious subjects, but actually painting peasants as they went about their daily business. He would dress as a peasant himself so he could travel incognito and mingle among his hoped-for subjects, and some of his results were the equivalent of candid snapshots of a social class and a lifestyle which other middle or upper class Europeans believed weren't worthy of observation.
The Peasant Wedding (1567)
Click! Unlike those 15th-century nobles who spent fortunes getting their portraits painted, only to come out looking like waxworks, these peasants still live and breathe over 500 years later.