The QR code contains the file URL not the file SHA1 Checksum. If you check the html for the image you will see the title text says "File download URL". It is common to see these codes in situations where you may need to download the file to a mobile device or access the webpage from a mobile phone..

Programs like QuickMark can be used to scan the QR Code from your phone, and if a site doesn't provide a QR Code you can use something like this Google Chrome QR Code extension to automatically generate one. I use both of these and use them once or twice a month.

You basically then just use the camera on the phone to take a picture of the webpage while it is displayed on your desktop computer and open the URL in the mobile browser, sort of like Copy & Paste between two computers.

A supposedly “dynamic” QR code is simply an alias to the final destination URL

The concept of a dynamic QR code is based mainly in the world of QR codes being used for URLs and such. The QR code itself is always static.

That site you link to doesn’t really explain it well, but it’s pretty simple: The QR code format is the same regardless of whether the the data is static or dynamic. But in the case of a dynamic QR code, the generated QR code is just a “middle man” of a short URL. As explained on QRStuff.com:

• Static QR Code: The actual destination website URL is placed directly into the QR code and can’t be modified.
• Dynamic QR Code: A short URL is placed into the QR code which then transparently re-directs the user to the intended destination website URL, with the short URL redirection destination URL able to be changed after the QR code has been created.

So if you were to create a QR code to Google.com, a static QR code would directly encode the URL https://www.google.com/ but a dynamic QR code would assign https://www.google.com/ to a short URL like something like this: https://example.com/iuyd9871.

That way the QR code always has that https://example.com/iuyd9871 URL embedded and (key point) what happens when one goes to that URL can be adjusted. So if you wanted that QR code to point to Bing, then you need to just adjust what that https://example.com/iuyd9871 will redirect to.

So that said, the weakness of a dynamic QR code is it relies on a service that manages that short URL. If that service is down or disappears for some reason, then that “dynamic” QR code becomes dead and useless. A static QR code will always work as the URL is always embedded in the QR code itself.