There are many yellow orbs like this one in Shoreditch. They are one of Otto Schade's trademarks (the second is the yellow ribbon which I'll show in a few days). "Osch" is a Chilean architect and an active street artist in London since 2009. His works incredibly seem to last a few years and are not painted over by other artists... coincidence or a form of respect? The yellow orbs usually tend to show a common theme: children and war, like this one in Hanbury Street.
Initially I thought that they were not fitting the context, ultimately, what war has to do with London streets? But when I recently read about the clown of Aleppo died under a bombing (in the news a few days ago), I realized how social awareness is fading away on the Syrian war, as well as similar conflicts around the world. With a notable sense of humor, his orbs remind us of that, without being pathetic. In this sense, he is very similar to Banksy
Picture taken on 31 October 2016 (Hanbury Street)
Another examples of Osch's famous yellow orbs are the ones below. In the first one children are pointing their guns at what seems a clown. Otto Schade has been probably inspired by famous Banksy anti-war stencils that appeared on Israeli wall along Palestine in 2007 and 2008