Optimizing the following images but I use WP Smush Pro


I use WP Smush Pro but GTmerix say:
"Optimizing the following images could reduce their size by 759.7KiB (46% reduction)."
"Losslessly compressing http://footballheroes.hu/wp-content/uploads/sites/11/2016/05/fiola_kep.jpg could save 13.3KiB (65% reduction). See optimized version"

What should I do? It's a real compression problem or just image dimensions?

Thank you,