I had the same reaction as @scor to the "A sub property of image" sentences, having never liked them much in the actions vocab either. But you're right we do use the phrase elsewhere. However now that the site has built-in navigation structures for sub-properties, my preference would be to simplify the wording of the Action-related subproperties and to avoid adding that phrase here. Does this make sense?

ps. thanks for the pull req :)

(I'll back out the comment changes manually.)