Happens all the time! It's awesome because you get to see it made, but sad because you feel like you can't make it now without looking like a copy. Truth is, people often have the exact same, or pretty much the same ideas at the same time, in totally different parts of the world. I guess sometimes great cakers think alike! Keep on caking, and don't sweat the small stuff. What matters is how awesome the cakes look when they're done.