There can be two case of it:
1. You are using scene7 for your digital assets, in this case you need to check whether you are passing the required PRESETS for image or not to get the required image to be displayed on the page.
2. You are using DAM for digital assets, in this case you need to verify the image in publisher DAM whether is fine or not means in size. If not fine then you need to upload the actual image in the dam.
If every thing is fine then for both of the case you need to verify the CSS or less whether it is rendering fine or not.
Hope this will help.
Umesh Thakur