Do you have it copied from somewhere else? Or linked from another place? That can be one reason.

It can also be that you were running out of memory on your computer, but I dont see your butterfly on mine either...so I imagine, it is probably the first thing I mentioned...

If it is, save it to your hard drive (the picture) and then upload it instead of linking to the picture...if you have NO IDEA how to do this, post such and I will try to help