There are two significant elements to this image:

1) A male who has been retrained to accept that arousal does not entitle him to intercourse or even orgasm simply for being erect. Instead, they both appreciate how it entitles her to enjoy a physical, undeniable expression of intimacy that runs very strongly against his base male instincts.

2) It is clear from the towel, bowel, and postures that this is a developed ritual that is as much about her enjoyment of accepting the gift of his retraining as it is about his eventual release under her control/direction/involvement.

Use of such rituals can greatly ease the mental/emotional struggle such males have with their retraining and serve as confirmation that their retraining has value.