Not sure if anyone has noticed, but the very first post in this thread is clearly not a Class 378 - for a start 378's have a staircase where the photographs centre window is, and the desk is more traditional than the VDU units in the photograph.
By deduction of the driving position being on the left hand side of the unit, and the window layout, it appears to be Bombardier Movia (S8-Stock) as seen on the LU Metropolitan line. (Rather than the Victoria Line stock I also thought it could be - but which have the driving position on the right hand side of the cab)