Previous Post Display Options?

Can anyone advise me on how to set my previous posts, that will display along the bottom of my current post page, to show as vertical with the little thumbnail or image, instead of square on top of one another? I only have a couple posts so hard to show you what I mean. I have Thesis WordPress.

This blog shows the square option previous post option I mentioned, see left side of blog under current post: http://www.artbizblog.com/

This blog shows the vertical previous post style I am trying to achieve, located part way down blog on left side: http://www.finearttips.com/

Thank you for any advise! 😉