Contrary to what you might think, this photo was not snapped over the weekend using Instagram's Valencia filter. It's known as Lenna. As Motherboard points out, it's one of the oldest, most widely used test pictures used for all kinds of image-processing algorithms.
The real name of the subject is Lena Soderberg, and the picture was actually cropped from the November 1972 Playboy centrefold. The name was later anglicised to Lenna. It was picked when an assistant professor at USC's Signal and Image Processing Institute (SIPI) decided late one evening that he needed something not totally boring to scan for a colleague's conference paper. Everything else was old and dull (read: lacked pretty ladies, lacked breasts) and so thank god for Playboy. IEEE told the story back in a newsletter in 2001 [PDF]:
They wanted something glossy to ensure good output dynamic range, and they wanted a human face. Just then, somebody happened to walk in with a recent issue of Playboy. The engineers tore away the top third of the centerfold so they could wrap it around the drum of their Muirhead wirephoto scanner, which they had outfitted with analog-to-digital converters (one each for the red, green, and blue channels) and a Hewlett Packard 2100 minicomputer. The Muirhead had a fixed resolution of 100 lines per inch and the engineers wanted a 512×512 image, so they limited the scan to the top 5.12 inches of the picture, effectively cropping it at the subject's shoulders.