When sharing my gigs picture does not show up.

[rabbit978]

I have created two gigs recently 

1. https://www.fiverr.com/rabbit978/translate-website-in-any-language-using-wpml-or-polylang

2. https://www.fiverr.com/rabbit978/develop-responsive-professional-wordpress-business-website

What i have noticed is when sharing these gig in twitter, Facebook the gig images does not show up. I have another old gig, when sharing that gig, image properly shows up. Any idea why gig image does not show for the new two gigs ?