Is my app billed every time an <img/> tag downloads the url from getDownloadURL?

[koroman17]

In an app, an avatar could be displayed at many places. If I use

getDownloadURL(avatarRef)
  .then(url => {
    imgList.map(img => img.src = url);
  })

is my app billed every time an img downloads the url? If so I think the better way is to download the image with xhr once and store it in the app like this

getDownloadURL(avatarRef)
  .then(url => {
    const xhr = new XMLHttpRequest();
    xhr.responseType = 'blob';
    let blob;
    xhr.onload = (event) => {
      blob = xhr.response;
    };
    xhr.open('GET', url);
    xhr.send();
    // when the blob is returned
    imgList.map(img => img.src = URL.creatObjectURL(blob);
  })