Featured image not showing on home page of a one page website

Site URL: http://marlin-crow-s2c4.squarespace.com/blog/5mgwomexx9p0jqoqv8ay88rxw99lhg

site in in trial mode so need password to view which is aaaaaaaa  that's 8 lower case a's 

and url is marlin-crow-s2c4.squarespace.com/blog/5mgwomexx9p0jqoqv8ay88rxw99lhg

So... 

I have a "one page"/ one menu link website. The one page/ menu link is "blog" 

However, when you go to the site url, the featured image does not show. Have to click on the hamburger menu and click on "blog" (the only link there) and then it shows the image (and this is how I want my home page to look) 

In settings, however, the little home icon is beside the "blog" section. So, it's like the blog is the home page but also there is another page when you write in the url which is a different home page. 

Help would be appreciated!! Frustration setting in. 

I realize this going to be a easy fix for somebody!

Thank you

Access Pages > Main Navigation > Blog Page > Hover blog posts >> look right you will see 3 dots > Click on it > Settings > You can edit featured image