It's not a great picture, but from what I can tell, that appears to be a picture of a legit FireRed cartridge. Of course, if you aren't sure yourself, Hikari posted a great reference page by Team Fail from a few years back. As with buying any games over the internet though, it's pretty easy to be tricked into buying a counterfeit item, so be sure to check the seller's reviews and be aware of any return policies in case the cartridge isn't legit (though, if you're getting the one pictured, you should be okay!).