Well, not exactly because you don't convert the positive rail to a negative one, but instead use the same transformer winding to get both the positive and negative voltage simultaneously. Still a neat trick though. Problem with this is that it has quite an insidious failure mode. You see, the two decoupling capacitors are polarised, and work fine now, but if the first diode bridge fails, the voltage on the capacitors becomes AC, and they might blow up as well. Basically a positive rail failure means a negative rail catastrophic failure as well.
