@AnOldGuy
Seems to be a smartphone stand/cradle which is included in JAL's amenity kits.
https://www.jal.co.jp/jp/en/inter/service/business/amenity/
"Another unique offering here, there is a foldable and adjustable smartphone stand plus an phone charging cord...Although apparently these cables are going away."
https://www.travelcodex.com/jal-heralbony-business-class-amenity-kit-review/