title: Why is there a 'Mixed Content' alert when calling images with a relative path on a https site?
body: <p>On my subdomain site (<a href="https://m.domain.com" rel="nofollow">https://m.domain.com</a>), I always have to call my images using absolute path (//domain.com/image/img.png). If I use a relative path  (/image/img.png). Chrome will have an error which says that it is a mixed content and http content should not be served over https.</p>
  
  <p>But I don't have this problem on my main site (<a href="https://www.domain.com" rel="nofollow">https://www.domain.com</a>). I can use relative paths without a problem. Why is the difference? Thank you.</p>