Here is this revised or updated Audi A4 for your consideration. I have marked in red all the areas that look identical with the outgoing car.
I conclude the glasshouse is the same and the bodysides to halfway down the doors are the same geometry. They have replaced the pronounced upward curving swoosh groove with a scalloped indent and the lower bumpers have been tweaked. There’s nothing wrong with this as such. It is however what looks incredibly like a mild facelift. It is not a new car.
Driven To Write 
On the outgoing model the grille is indented slightly into the trailing edge of the bonnet. On the new model, the trailing edge of the bonnet is a flat shape set over the grille. Of such small details, an “all new” Audi is born.
As someone once said and I like repeating: if you have to measure a difference you haven´t really made one.