My image quality is low after using a copy of the original theme

[Alex591]

Hello,

Today instead of editing the code on my copy of the theme I edited the original copy and messed it up badly so I have to use the copy of it. And by mistake, I deleted the original theme and I only have copies of it. Now my photos are low quality and I sincerely don't know how to solve this. I worked hard to make this site look good so I wouldn't want to start a new one. Could someone help me solve this problem? 

Here's the link: https://64026d.myshopify.com/

Thank you!