Picture size

Please add this CSS in wp-admin >> Appearance >> Customize >> Additional CSS to fix this.

.single-service.postid-179 .service img {
    width:auto;
    height:auto;
}

This will force image to use its right size instead of taking the full available width. 

This is featured image set there. 

Cause of a code this is visibility hidden which you may added for some other purpose, if you want to keep this image on post page, i will send you fix else you can just remove the faetured image of your page.