Image attachment clipped/cropped

Hey guys! I’m struggling with a theme I’m editing, for some reason, when displaying the full post, the attached image (which I have set to be full-size) is cropped or simply clipped somehow, so that only part of the image shows up.

I’ve checked in the functions.php of the Imbalance theme that I am editing, I’ve tried changing this piece of code;

$attachment_size = apply_filters( 'twentyten_attachment_size', 900 );
							echo wp_get_attachment_image( $post->ID, array( $attachment_size, 9999 ) ); // filterable image width with, essentially, no limit for image height.

But I’m not quite sure what to change it to for the image to appear in its entirety, nor if it is this piece of code that I have to change.

Does anyone know what I might have to change?

Here’s the link for the website;

https://www.esmone.com

If you click one of the posts, you’ll see that the image is clipped off somehow, yet there is a border around where there should be a full image.

Any help on this issue will be much appreciated! ??