image height not changing – using image widget

Dear MMM Team,

I am using the “image widget” plugin with 4 images in the first row of the mega menu. All the images are square in aspect ratio. However, the images are getting elongated when changing width of the browser window.

What needs to be done to avoid this?

website: http://www.walldesign.in

Thanks
Rahul

https://wordpress.org/plugins/megamenu/