Resizing Images

Site URL: https://www.aindustria.pt/shop-online

When I try to upload a picture of my bags\briefcases the template I use automatically resizes them and crops them to a specific dimension. I had to add a banner to the pictures so that they wouldn't appear cropped. How do I change the image template to the appropriate dimensions for the picture?

The images attached show one picture with the banner the other picture without. 

I"m having the same issue with my art images