Something people worry about, including me, is making a picture that looks just like someone else's picture.
If you're in the land of the Single Iconic Image, then when you shoot something that looks a lot like Lange's "Migrant Mother" you're simply making a cheap knockoff, or at best, a very good knockoff. If you duplicate it with changes, perhaps you're commenting on Lange, on the original, or something, but it's still pretty lame.
If instead you are making something bigger, a portfolio, a book, something else, then there's an additional and important layer of possibility. You can quote Lange, literally or figuratively, in order to create a link to that work from your own. There are a bunch of reasons one might productively do this.
If you're writing a poem, and you simply lift couplet from Shakespeare, you're a plagiarist.
If you're writing a novel, and you quote Shakespeare, that is quite a different thing. You could be quoting Shakespeare for terrible reasons but, again, there are a bunch of reasons one might productively do this.