Hi TopSpots...sorry for late replay as I see WP does not send notifications.
The theme does use thumbnails for each post intro, whether you have the blog as the front page or if you are using the Static Front Page method of WordPress where your blog is inside and not on the front page.
With a post, you would use the "Featured Image" method that WordPress has in the lower right column in the post editor page. You get the option to use wide intro images or small. This can be set from the theme's Customizer for theme options.
I'm not sure if you are registered on my site for support, but there is a link in the theme files called Readme.html which has a link to register (free of course). This will get you access to detailed documentation (with screenshots) for all of this and more.
IF you still run into problems, let me know. Long story short, you have the option to use small or full width featured images on your post intros. I do recommend cropping and sizing your images before uploading as this gives you a lot more control over how your thumbnails look.