This is the "A Man with a Pink" painted in the Italian north by Andrea Solario. The painting commemorates the marriage of a Venetian man of high rank, whose identity remains unknown.
Notice how he's dressed in the latest fashion, using a three-quarter pose set against the background of a green valley. This style was innovative at the time and was adopted from contemporary Netherlandish painting. His outfit tells us he was likely a magistrate or member of one of Venice's councils.
Take a closer look at his hands; what he holds and wears is key to understanding the painting. The pink flower in his hand suggests that the portrait commemorates his marriage, as it was a custom for brides to hide pinks in their clothing on their wedding day. His other hand clutches his stole, showing off the blue and gold ring on his thumb.
The artist has used various techniques to create the impression of a vast countryside in the distance. The two trees framing the man's face mark out the centre ground, while the river behind him leads the eye towards the mountain range.
A Man with a Pink hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.