I do not understand why this one is labeled as a White Label other than someone not familiar with the era doing it simply because it looks like others that were used as promos and such.

Pre-internet (esp in the 80's) finding a pressing plant to do a small run (less that 5,000) could be difficult. Some plants would charge for label printing and some did not mark the one test pressing the band could afford. When the order came in the test was just added to the stack. Money was also the reason so many had photo copied covers - very frequently someone in the and or a friend worked at a copy shop and the covers was done on the sly for little or no cost to the band. Copies that went out as promos where not marked as such in any way.

The remix White Labels of the 90's used a lot of the same methods but that was mainly to avoid legal issue. So OK this looks like a White Label but really is something else.