RSS Feed Help

My problem is that my gravatar picture is on every single on my post. Every time I post a new post it only shows my gravatar picture as opposed to one of the pictures from the post.

When my post shows up on Bloglovin’ the thumbnail that it displays is my gravatar picture.

Here’s my website: http://vincent-ko.com/
RSS Feed: http://vincent-ko.com/feed/
Bloglovin: http://www.bloglovin.com/en/blog/1959444/vincent-ko-photography/follow

Can someone please help me? Thank you.