I have noticed street art from Core246 and Kaes in London before, but the largest-scale piece from them that I have seen has been a mural on Old Street that has appeared on RED Gallery. The subject of the work is Japanese American performer Ayakama. Her work explores the relationship between photography and performance.
More about the stunning piece from one of the artists can be seen here: http://www.jaykaes.co.uk/PRIVATE. Around the corner form the new mural is another small mural on scaffolding.
The artists' Facebook pages can be found here https://www.facebook.com/iamjaycaes/ and here https://www.facebook.com/core246