Your first paragraph is a more academic form of what Nate stated about it, funnily enough. The bass (though not strictly alberti, per se) was just to vary the pitch a little. It is quite clear that it would be much better if there was a much less bombastic introduction, but since I don't actually play the piano - yet - It's all I could think of on a whim.
I was admittedly interested in developing it, but I feel since it literally took 5 minutes of my time, I could just as easily do it again, a better job with some better layers and a lot more variety.
It's not quite an extemporisation because as I mentioned (I think, I don't remember where), there was a slight plan involved. A mood and such, and I did have a natural inclination as to where to follow through, whether it be good or not. And since it isn't *literally* random, I think Improvise is an entirely apt word.
Thanks for the input though, despite the trollish nature. (me not you)