Thumbnails with posts not showing

Hi,

I am using the emag (flexi theme). I created the site to where my posts appear on the home page. I included a photo in the posts, but these photos are not showing in the post excerpt on the home page. The site looks bare without these images. Please help. I am not an expert, so any step by step would be appreciated. I tried researching the developers site as well as contacting them via email…no luck..