Featured image not pulling through on Facebook LinkedIN posts

Hi there, I need some help. When I post a copy of my WordPress site’s URL (www.gocuplin.com) into either Facebook or LinkedIN neither site is able to pull through my feature image or site description. These are both just blank and look awful. It is very important that these work as sharing on these two sites is key for my site’s growth. I’ve set the featured image consistent on all my pages and posts. What am I doing wrong? I’m running 4.1.1 running Optimizer PRO theme. Thanks in advance. Matt