1) Add option to proceed with low res photo OR re-upload a high res.
! Your photo is low resolution. Your canvas print may turn out pixelated / blur with this low res photo.
For a great canvas print, a photo with minimum 3MB is recommended. Are you sure you want to continue?
Option 1: Return to Upload New Photo Option 2: Continue with this photo
2) Display 'size' Eg; 30kb in red if less than 3MB, black if more than 3MB of uploaded image on Order Details Page on admin panel