Response to Picture in Picture review comment

Back in April I provided APA feedback to the Picture in Picture API and
entered the following comment to that group:
"As a representative of the Accessibility Platform Architectures (APA)
working group I reviewed this specification for accessibility concerns. One
accessibility use case we see is the display of sign language translation
within the picture in picture window.

I am trying to understand who is responsible for generating the user
interface to find and switch between picture in picture windows? Is the
browser responsible - similar to the controls provided for the video
element? Or, is the web developer responsible for including the user
interface? Either way, it is imperative that this interface meets the
requirements of WCAG 2.1. We are asking that you add an accessibility
statement to the specification that outlines the requirements for meeting
WCAG 2.1 and especially of the mechanisms for a user to find,
enable/disable, and navigate to/from the picture in picture." <
https://github.com/w3c/picture-in-picture/issues/179>.


They have asked for clarification and examples. We discussed this a few
weeks back and Janina suggested that we could use Lionel's response to the
Web Hints specification as an example.  I don't really believe that fits
the picture in picture situation.


I am also wondering if an API specification really needs to provide
specific WCAG guidance and reference to specific success criteria.  Isn't
it enough to just remind people of the WCAG requirements within an
accessibility statement?


I am inclined to reply with the following suggestion for an accessibility
statement:

It is imperative that the interface for picture in picture meets the
requirements of WCAG 2.1. All users must be able to find and navigate
to/from the picture in picture, and enable/disable/operate all controls
using various input modalities, color and contrast settings, and assistive
technologies.


Does the group believe this is a sufficient response or do we need to dig
deeper?

thanks,

-becky