I was thinking your motivation was to reduce some real-world harm. E.g., images sitting for a week causes difficulty X to person Y. I gather you're saying it's a more abstract thing, an aesthetic preference?
The real world harm is that of copyright violations. IANAL, so I don't know if it is actually illegal for us to have unfree images on the site for a week without them being fair use, but it has to be quite close to that fine line. Just because we can't technically be punished unless we refuse to remove it upon request doesn't make it legal for us to keep it there until that request is made (by my understanding of the law - if I assault someone, I can't be punished unless they decide to press charges, them not pressing charges doesn't make my act legal, though).