Realties Gallery stretch problem

Hi,
I notice that the gallery in the item page stretches the images in a bad way (picture attached).
Could you suggest me if there is any way (by settings perhaps) to avoid it? Or if theres a native proportion to respect?

Thanks a lot.

Dear Supergap,
Thanks for contacting us.
Please give me link your site and your account of administrator via private messages,i don't login your account sent me
I will check it for you.
Best Regards,
Vinh Falcao