Parsoid's image tags don't have the alt attribute. See below
<img resource="./File:Foo.jpg" src="//upload.wikimedia.org/wikipedia/commons/0/06/Foo.jpg" data-file-width="300" data-file-height="197" data-file-type="bitmap" height="197" width="300" data-parsoid='{"a":{"resource":"./File:Foo.jpg","height":"197","width":"300"},"sa":{"resource":"Image:Foo.jpg"}}'/>This needs to be fixed