I was expecting to read some story about criminal exploitation, but this sounds like it's just... completely above-board? As a few other commenters stated, the model hasn't explicitly stated whether she supports the use of the photo or not. Even if she did explicitly come out and say she doesn't like people using it, she doesn't own the rights to it.
I'm fine with (and happy for) people going above and beyond to respect someone else's dignity, but this is less about ethics and more about one person's potential regret over a business transaction. Just because you regret doing a deal doesn't mean others are unethical for benefiting from it. When you're using your own body in a business transaction (of _any kind_) you should really think through the possible consequences. Whether it's getting a tattoo or putting your kids on TV or selling photos to Playboy, those all have ramifications you won't be able to control very well later on.
I'm fine with (and happy for) people going above and beyond to respect someone else's dignity, but this is less about ethics and more about one person's potential regret over a business transaction. Just because you regret doing a deal doesn't mean others are unethical for benefiting from it. When you're using your own body in a business transaction (of _any kind_) you should really think through the possible consequences. Whether it's getting a tattoo or putting your kids on TV or selling photos to Playboy, those all have ramifications you won't be able to control very well later on.