We're looking here at an original BMB CD-i Master Controller CDI-M1500. It is a Karaoke player from Japan, although to us it is a bit unclear what type of discs it supports. The controller needs the CDi-A1500, which is a CD-i Auto Change Player, I guess a multi-disc holder that picks out the disc of your preference. Philips also planned a CD-i carrousel disc changer but that one was never released.
These Karaoke players are always a bit of a mystery to us. We've seen Karaoke Players before that actually have an original Philips Digital Video Cartridge onboard (the large one). These players support the VCD standard, in principle these players play all Video-CD's. But the one we see here, produced by BMB / Nikkodo actually havs the official CD-i logo on the bottom right. Moreover all types start with CD-i. That's typical, it suggests this player accepts all CD-i discs.
For now this will remain an unanswered question: Our CD-i community has never shown anyone who owns one of these machines. Maybe one day....
[Credits: CD-i members Gluon Van, Retrostuff, Rosanayuji]