If you want to block out all summary images across your site, I believe this CSS will accomplish it. You will need to add it to your custom CSS section -- 'Change Style' (painbrush icon) > 'CSS'
.summary-thumbnail img { display: none; }
.summary-thumbnail { height: 0px; }
If you want to limit this code to a particular page, you can either find the collection ID for that page, (which I found on your site and I'm using for the example code) and add that to the CSS code (in the master CSS file) like this:
#collection-512f74b7e4b0c3388795a028 .summary-thumbnail img { display: none; }
#collection-512f74b7e4b0c3388795a028 .summary-thumbnail { height: 0px; }
or add it to that particular page's 'Page Settings' > 'Advanced' > 'Page Header Code Injection'
but you will have to add
<style> tags around it, like this:
<style>
.summary-thumbnail img { display: none; }
.summary-thumbnail { height: 0px; }
</style>
