FWIW I've never had this happen to me. I do get ads shown to me on Facebook after doing a Google search for something, but that has more to do with Google and Facebook, and less to do with my phone. If you're getting email marketing, it's very hard for me to understand how the data could have been extracted from your phone's photo gallery and propagated to whatever marketing service is doing this. Not saying it's impossible, just a little beyond what I understand to be most tech companies' current marketing ability.
Maybe try turning off your Gallery's image analysis feature (that's the feature which classifies your pictures as, e.g. "food," "wildlife," etc.). Then see if you get fewer marketing emails. And what others have said about disabling app permissions is also good advice.
08-16-2017 08:22 PM