Several various sites are built in a way that would not allow them to grab the images off of their website:

• The website is built with widgets and not regular HTML (ex. Wix sites) 
  
  
• The images are of low quality (less than 300px)
  
  
• The website images are too small or too large(ex. less than 100Kb or more than 2MB)
  
  
• The CSS of a website is protected from access (Ex: apple.com)

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