A lot of things going on with this image that make it really interesting to me. For one thing, there's pretty strong evidence that in the UK the tawse (in Scotland) and cane (most of England, Wales and Northern Ireland) were the favoured implements used for corporal punishment in school during the 20th century, the slipper (usually, in practice, a gymshoe/plimsoll/sandshoe/dab) was often the secondary choice, and probably, as such, gets under represented in the adult CP sites that try to depict "school" type scenarios.
In some schools, the standard rule was apparently that boys got the cane and girls got the slipper. Where girls were subject to the cane, it was usually given on the hand, but it is generally the case that the slipper could only really be effectively applied to the bottom - hence in treating girls with the apparent leniency of the slipper rather than the cane, they were nevertheless exposing them to the greater humiliation of being punished on the bottom rather than the hands.
It was also, to a large extent, the case that if the person inflicting the punishment chose, the slipper could hurt almost as much as the cane (although the pain from a caning probably lasted for longer) so that those on the receiving end were probably not being given credit for how serious their punishment was. After all, if you cane someone across their bottom, you need to stop the stroke at some point shortly after impact or risked damage to the cane - because the slipper flexes much more you can apply as much force as you want.
Another common rule in UK schools was that, where corporal punishment was to be used on girls, it could only be given by a female member of staff. Of course, this rests on the assumption that male staff hitting a girl might derive some enjoyment or might be able to hit harder than necessary. Of course, the reality was that there were probably some female members of staff who were more attracted to girls than boys and could get quite a kick out of physically punishing one of them. I suspect that in some schools the girls would have their suspicions about some of the female staff and would probably have preferred to be punished by a male teacher if they had the choice. It would probably also be the case that many male teachers might hold back a bit when punishing a girl whereas a female member of staff may not feel the same need to be sparing.
There is also a widespread view on sites that depict corporal punishment of "schoolgirls" that skirts would either be so short that if they had to bend over, their knickers would be exposed or, alternatively, that the pleating and volume of material in the skirt would impede physical punishment and necessitate it being turned back. Both of those were, probably, often the case, but some girls did choose to wear quite tight pencil skirts and bending over then would simply tighten the material across her bottom in much the same way that boys trousers were tightly stretched by the act of bending.
This image is taken from the magazine In Uniform and In Disgrace - I believe this was a one-off special from the team that produced the Strictly Uniforms magazines.


















