You see the problem – the image you chose is partly hidden behind the page title or post title.  This code is tested with Twenty Fourteen. You need to add it to your custom CSS file.

.full-width .site-content .has-post-thumbnail .entry-header,
.full-width.singular .site-content .hentry.has-post-thumbnail,
.site-content .has-post-thumbnail .entry-header {
margin-top: 0;
}

More Posts About Featured Image problems in twenty fourteen

• Moving the Page and Post Heading Down to stop it obscuring featured image in WordPress Twenty Fourteen
• Replacing the grey striped background of WordPress.com Twenty Fourteen featured image with white CSS