You can read on Flickr forum
We are going to re-introduce the HTML embed option to the new photo experience. It will be live on Tue 3/18. This now gives you two great options to integrate Flickr content into your web experiences: with the Flickr Web Embeds and the popular HTML embed code that you asked for.
- the title of the link for every photo is title=”Untitled by , on Flickr”
- the alt of the image for every photo is alt=”Untitled“
This means that Flickr doesn’t use the title description of every image but simply use Untitled!