Featured image dimensions…

Hello, A strange problem with Featured images... On www.coccole.net every image i set on the post get cut ... in practice a cat lost hears for example... A portion of image get dropped... How to see for fixing? The problem is that i see the complete image at 250 x 250 ad example but after added as featured it becames smalled, reduced by a portion... nothing modify changing the resolution or scaling with wordpress or pixel mator graphic... I lost hours for easy things but i have no idea where to see in the theme for resolving... see there the chick how is cut http://www.coccole.net Thank you Luca