How do you know when you've killed it?

I started making this Ishbel before we moved - when I was waiting around to heard about the closing.  I used some mystery cone of something - there was an unattached label inside the cone that said it (assuming "it" is the cone this label corresponded with) was nylon and acrylic.  it's sparkly and blue.  that's all I know for sure.  I finished it last week, but dropped a stitch or two during the bind off and kind of made a mess of it.  I fixed it enough and blocked it today.  Assuming it was acrylic, I figured I'd kill it with steam so I pinned it out on the bed, put a damp sheet over it and turned the iron to steam and ironed the heck out of it.  So my question is, how do you know when you've actually killed it?  I  know it's supposed to get shiny and drapey.  I'm not sure this is shiny-er than it already was, or drapey-er than it was.  it's flatter, but that's because I ironed it.  I suppose I'll know if I wash it and it holds this shape.  Considering that I don't actually know what the yarn really is, I'm quite sure I won't be throwing it in the wash.  I suppose at the very least, whatever it is, has been steam blocked!  And it's pretty!  

Ignore the stupid look on my face here.  Believe it or not, this is the least stupid of the 50, or so, pictures I took!  geez.