images do not show on main page, only text headings..

I’ve installed the theme and what attracted me to it was the fact that the images displayed on the home page for all posts but in reality i’m only seeing the post titles appearing, any idea how i get the images to display? just like it shows in the theme advert pic.
(It may help to know that before this i tried a theme called The Newswire and had the same issue here which is why i switched hoping to get a theme which displayed the image+post heading.)