I tested posting a blog post to Facebook it shows a too large pic of the header title design you made for the home page not blog image. It doesn't show the feature photo from that blog post. Also, when I share a blog post link via text, it doesn't show a thumbnail photo of that blog post's feature photo, just words. When I post to Twitter, it only shows the URL, no photo. In Instagram it open account but no sharing functionality. Here is my code.
<a href="http://www.facebook.com/sharer.php?u=<?php echo
urlencode(get_permalink()); ?>" target="_blank" class="link" title="<?php
esc_attr_e('Share on Facebook', 'cheerup'); ?>"><i class="fa fa-facebook"></i></a>
<a href="http://twitter.com/home?status=<?php echo urlencode(get_permalink()); ?>" target="_blank" class="link" title="<?php
esc_attr_e('Share on Twitter', 'cheerup'); ?>"><i class="fa fa-twitter"></i></a>
<a href="https://www.instagram.com/share?url=<?php echo urlencode(get_permalink()); ?>" target="_blank" class="link" title="<?php
esc_attr_e('Share on Instagram', 'cheerup'); ?>"><i class="fa fa-instagram"></i></a>
<a href="http://pinterest.com/pin/create/button/?url=<?php
echo urlencode(get_permalink()); ?>&media=<?php echo urlencode($media); ?>&description=<?php echo urlencode($title);
?>" target="_blank" class="link" title="<?php esc_attr_e('Share on Pinterest', 'cheerup'); ?>"><i class="fa fa-pinterest-p"></i></a>