I was running into some accessibility audit errors with Jupyter Book, and it made me realize that the _repr_html_ method of Figures doesn't output img elements that have alt tags (something that screen readers like).

It seems that the relevant code is here:

and then uses the template that's referenced here:

Maybe using this?

https://github.com/matplotlib/matplotlib/blob/be978a35932a9f303f3d60f14f52ed9df89334c5/lib/matplotlib/backends/web_backend/js/mpl.js

I wonder if this could be a relatively simple fix by making the figure title the alt tag by default, and if it doesn't exist, just making it something like Figure?