Expose webcam/phone cam information to researchers

TL;DR

Especially as more people successfully use jsPsych, we are getting more phone data, which means more phone cameras...which might mean receiving more mirrored data. Keyword might - I don't actually know what's true for the selfie camera, but this is a lot of the problem. Researchers need certainty about the directionality and can't always count on incidental text in the background.

Hi! My lab's current study is having issues with some recordings being inverted so we aren't able to tell which side of the screen the babies are looking at. Is there any way to standardize the cameras or implement a calibration so we know which side is left/right for the infants?

• Slack post

Implementation: This could pair well with generally exposing more data about the participant's device & browser: what can we get from EXIF, versus what new data would we potentially need to be (trying to responsibly) detect during the study? This can be very helpful for debugging, on top of researchers wanting to understand whether participants are using phones, laptops, or tablets.

Include with this update some docs that help researchers understand this, including the kinds of in-session tasks/calibrations that researchers should include for backup! (Holding text up to the screen, labeled right-left calibration looking trials, adult pointing to own L and R, etc.)

The issue names no files, tests, or entry points, so begin by mapping the existing webcam-recording and participant device/browser data flow in the Python API and jsPsych studies. Define which camera and device information can be exposed responsibly, then document the resulting data and recommended in-session left/right calibration tasks for researchers.