I don’t walk that way every day (I avoid the tube and walk the backstreets when I can) but I’ve not seen one out recently. They may have just sold out.
It’s the house with the black window frame and white woodwork that used to be a shop on the corner here: https://www.google.co.uk/maps/@51.5045748,-0.1090211,3a,75y,112.63h,88.54t/data=!3m5!1e1!3m3!1sxWWU9zI6pntPCfPhv0E2HQ!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DxWWU9zI6pntPCfPhv0E2HQ%26output%3Dthumbnail%26cb_client%3Dsearch.TACTILE.gps%26thumb%3D2%26w%3D96%26h%3D64%26yaw%3D80.227295%26pitch%3D0%26thumbfov%3D100
Roupell Street is the last remnants of the older, residential history of this part of London. It’s not uncommon to see movies and TV filming there.