They both do this, you're just used to the furries.
It really depends on what he means. I often use an animal (though rarely very anthro, because those usually look stupid) avatar, but never post other furry images. I'm not too uncommon in that respect. Some "bronies," on the other hand, use exclusively pony reaction images, a pony avatar, and ponyful signatures. Of course, it's possible I just don't notice the furry stuff, so wh'ever.