Does the phone-based photo of W-2 work? Is it just currently broken? I tried twice but each time the link fails ("we're sorry, we can't find the page you requested.")

Don't import it. It's just as easy to manually enter the W2.  and the import could import it wrong.

To add a  W2 just type w2 (small W)  in the search box at the top of your return and click on Jump To the W2

OR  To Add a W2 enter it under

Federal Taxes on the left side

Wages & Income  

Then Wages and Salaries- Click the Start or Update button