title: What is the role of the key in a Google Photos Album url?
body: <p>Go to your Google Photos Albums page and hover over an album thumbnail. You'll see that an album's url looks like this:</p>
  <pre><code>https://photos.google.com/share/AF1QipN2T_IX-a4TjilksiuioY12GFNF59N-zaZQpz5vrD-QStk5C3FaLDJ1c5s1p_SJUJY5kA?key=MF9WbC0zRmpVZFQxTk9hT1lWdGVjUjV4UzRFbE
  </code></pre>
  <p>Does anybody know the role of the key?</p>