(https://home.kpmg.com/xx/en/home/insights/2017/05/flash-alert-2017-092.html) It also says on the above website about the time between graduation should be at most a year.
Although you graduated more than one year ago, is there any documented date which gets you inside 12 months? The date on your parchment maybe?
My degree was in Wildlife Media, and I have worked as a photographer, so could I apply for a J-visa on that basis?
Photographers are regarded as journalists for visa purposes - basically any content creator is a journalist. You can always apply, but it is a situation where you pay your money and hope for the best. Note that there is a requirement for a letter from your employer as part of the J visa application. In all cases there is no refund if you are not issued a visa.
Any other advice you could give would be much appreciated.
That depends on how desperate you are to take up the offer. Left-field suggestion - can you enrol in a post-graduate course, claim the internship as part of your studies - and apply for a student visa instead? Again, there are no guarantees in any of this.
Good luck!