It looks like your theme is dictating that presentation in it’s stylesheet. You can override this using the WordPress Customizer, and going to the Additional CSS section to ensure that you don’t lose your custom styles when you update your theme.
Glancing at the page, this CSS should help the other pages have the same presentation as the home page by overriding the properties set on the custom header image:
body.has-intro:not(.home) .intro-media img {
max-width: 100%;
margin: 0;
-webkit-filter: none;
filter: none;
-webkit-transform: none;
-ms-transform: scaleX(1);
transform: scaleX(1);
}
You can read more about this feature, and get more familiar with how to use CSS in WordPress in the codex: https://codex.wordpress.org/CSS