An animation refuse for young and old to celebrate friendship, generosity, honesty, laughter, kindness and loyalty.
All mixed together with some magical songs, crisp easy to replicate flash animation and plenty of content to appeal to all ages.
But I'd want to expand.
A Brony is more than just that.
Brilliant; creative and innovative, bronies have made songs, stories, comics and even entire fan-made episodes featuring the colourful cute heroes of the show. Full of inspiration the always elegant Rarity a white unicorn with perfectly styled mane and tail reminds all bronies that creating things is amazing.
Receptive; Love and tolerate is one of the key messages that the brony community promote, be nice to everyone, even those that don't like or openly hate you. Just like the most colourful of ponies, the pegasus Rainbow Dash with her rainbow coloured mane and tail tells everypony that Loyalty to each other is what makes the world a better place.
Optimistic; Laughter is one of the main (or mane...) elements of harmony embodied by the infamous fourth wall breaking Pinkie Pie, many bronies favourite pony with her bouncy pink hair and balloon cutie mark Pinkie Pie above all ponies reminds us to laugh, sometimes even at ourselves.
Nice; Such a understated quality in today's society, kindness, selfishlessness.
Real kindness changes people in act of the doing of it, often in amazingly unpredictable ways. Bronies have raised so much money for charity and good causes it is hard to estimate the exact amount but millions would probably be the starting number.
Just like the soft spoken yellow pegasus the prefers the ground; Fluttershy teaches us compassion and kindness is one of the best ways to keep friends.
Yourself; Or more accurately themselves, they don't have to pretend to be anyone else, they can happily and honestly just be who they really are.
If who they are involves watching a tv show with colourful pony characters on it, so be it.
Being able to be honest about themselves often brings out a great deal of the person's character not having to worry about hiding this element of their personality down bronies are usually more outgoing and friendly then many.
Like the reliable Applejack, honesty is the best policy, even if it's being honest with yourself.
That is the magic of bronies, it's not just individual elements, just like the show magic makes it all complete.
Like Twilight Sparkle, the now regal alicorn pony (that's unicorn and pegasus at the same time if you were curious) finds during the show you need friends, you need people that can understand you.
Bronies need each other, a community of people, all interested in a show about colourful talking horses.