in Customizer > Layout > Blog –> Featured Images >>> Archives.
You can select a smaller Image size eg. Medium, and then set the Alignment to Right and its Location to Above Title.
What do you think? I personally think the articles need some kind of separation, a border around them or a line between them.
You can achieve the same “separated container” look from the reference site by going to Appearance > Customize > Layout > Container and set the Content Layout to “Separate Containers”. https://share.getcloudapp.com/KouZOgKx
If you wanna replicate the sidebar position as well, you can go to Appearance > Customize > Layout > Sidebars and change the Blog sidebar layout to “Content/Sidebar” so the sidebar is on the right, similar to the reference.