Images aspect ratio destroyed when resize Windows browser

Hello. I have just bought the pro version and I am having the problem shown in this video:

https://youtu.be/63KOEpjHSoU

When I resize the browser windows or try diferent resolutions, the plugin destroys the images aspect ratio.

Could you please help me to solve it?

Thanks, best regards.

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