Images when sharing posts on social media?

You will want to add social media meta tags to your template. There is a guide to meta tags for social media on CSS tricks. Here is a complete example of meta tags that will work on Blot:

<meta name="description" content="{{> description}}">
<meta property="og:type" content="website">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" property="og:title" itemprop="title name" content="{{> title}}">
<meta name="twitter:description" property="og:description" itemprop="description" content="{{> description}}">
{{#entry}}
<link rel="canonical" href="{{{absoluteURL}}}" />
<meta property="og:url" content="{{{absoluteURL}}}">
{{#thumbnail.large}}
<meta name="twitter:image" content="{{url}}">
<meta property="og:image" content="{{url}}">
{{/thumbnail.large}}
{{/entry}}

You will want to add these to your template's head.html file.