This is the "Adoration of the Shepherds" painted in the Italian north by Niccolò di Pietro Gerini. It's a beautiful example of early Renaissance art, and what makes it even more interesting is that it was often collaborated on with Jacopo di Cione.
The altarpiece comes from the Clare convent of Santa Maria di Monticelli, and it dates back to 1383. You can see the tempera paintwork on wood, which gives it a distinctive texture. The level of detail in this painting is impressive for its time - look at the intricate folds of the robes, the gentle expressions on the faces.
The scene itself depicts the moment when Mary and Joseph discover Jesus in a manger after his birth. It's a serene and peaceful image, and I think it's lovely to see the quiet devotion that Niccolò di Pietro Gerini aimed to capture here.
Adoration of the Shepherds 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.