This is an excellent question, Mistress Lady! Not that dollyanne has done this of course, but, as You say, You can have your sub video a self spanking session or take pictures of a very red bottom result. Dolly has also heard of Mistresses who use web cams to have their sub perform for them while they watch, and of course, demonstrate their chastity. There are some punishment writing examples in one of Mistress Michelle's photo galleries that also demonstrate one way to punish. Getting tan lines is also something that can be demonstrated by photo.
Of course, it is difficult to verify that some punishments are really being carried out. For example, if You want Your sub to take a cold or cool shower, what is to prevent them from turning it to warm? Or, if You want them to buy a humiliating item in person how can You verify? Some Mistresses try to use receipts or notes written by the sales clerk, but this is something that also might be faked.
Ideally, if You had an accomplice local to Your sub, then he/she could personally verify things like chastity or even administer spankings or other punishments for You. That is probably the best case, but difficult to achieve in practice. For some things, simple trust and honesty on the part of Your sub are paramount. Someone may get away with a few things, but in the end they will get caught. If someone really wants to be Your sub, they should give You that commitment and loyalty!
These are just a few random thoughts, Mistress. Good luck to You and Your online sub!
Curtsey,:butterfly:
dollyanne