I don't really know that my look has changed, so or as much, as my uses for Second Life.>.>
My second life started on a very academic note on another avatar, then took on a Victorian aesthetic and then ultimately a kind of whatever-i-am-done-taking-my-e-self-so-seriously bend.
I couldn't find any pictures, other than group pictures, from early 2007 or 2008. I think I deleted them in a "I'M QUITTING SL FOR FOREVER" fit. Probably after some e-breakup. I do wish I had pictures of me being a super-noob though.
So, overall I would say my fashion has become increasingly less formal despite current tie. Oh, and I'm a lot shorter now too. No more 6ft tall woman av for me! =^.^= My whole second life from 2009 onward though is mostly catalogued on flickr.
In order of skins:
2007- Terrible freebie skin
2008- LAQ
2009- ROMI
2010- Gala/Curio
2011 - Leafy