Adding a name to an element without a role, like span or div, is technically invalid; in this example, only the <ul> elements have valid names added to them, because they implicitly have the role of "list."
Also, aria-label and aria-labelledby replace the contents of an element when the contents would otherwise be the name; if the <span> elements where <p> instead (which has an implicit role), screen readers would only read "IMDb rating" and not "IMDb 8.2."
What might be happening is the aria-label attributes are ignored but the title attributes are used as a description after the contents. For some elements `title` can be used as an element description; I think descriptions are also invalid without a role but they may get used anyway.
I think it's best for a visualizing tool to not display attribute information that won't be used by screen readers.
Also, aria-label and aria-labelledby replace the contents of an element when the contents would otherwise be the name; if the <span> elements where <p> instead (which has an implicit role), screen readers would only read "IMDb rating" and not "IMDb 8.2."
What might be happening is the aria-label attributes are ignored but the title attributes are used as a description after the contents. For some elements `title` can be used as an element description; I think descriptions are also invalid without a role but they may get used anyway.
I think it's best for a visualizing tool to not display attribute information that won't be used by screen readers.