Image is getting strectched

My sample image sizes are 600×600 and they’re circles. For some reason, all my images are stretch so they look like a 2D egg on it’s side.

This is the code that was generated by your plugin. How do I fix this so I have nice round circles?
[hover category=”logo-set01″ effects=”square” style=”style1″ item_show_row=”rd-col-lg-4 rd-col-md-4 rd-col-sm-6 rd-col-xs-12″ bg_color=”rgba(191,0,0,0.31)” circle_animation=”left_to_right” google_font=”Roboto” title_font_size=”18″ title_color=”#ffffff” title_font_style=”normal” desc_font_size=”14″ desc_color=”#ffffff” desc_font_style=”normal” button_font_size=”16″ button_color=”#ffffff” button_font_style=”normal” border_color=”#ffffff”]

https://wordpress.org/plugins/rd-hover-effects/