I don't think that this Korg Ek-50 has a "Midi Mirror" function, it's an entry level keyboard, but a pretty decent one. I like the fact that you can run it off of 8 AA batteries.

(little off topic)
Can't make a decision which keyboard I would want, the Korg EK-50 or the Yamaha EW-410 (also battery powered). I wouldn't mind to have a keyboard that I could take camping with friends, or to play it on the corner of the street.

Yamaha Ew-410 has 750 sounds, 250 Styles, 10 user styles, plays/records Midi and Audio .wav on a USB flash drive, it has 76 keys, but No Bass Inversion, also has a USB type A (for storing songs), it also has USB type B to host, that sends out Audio signals besides Midi to a computer.

Korg Ek-50 has 700 sounds, 280 styles, plus you can upload 90 user styles, it also records Midi and Audio files .wav, it plays back .wav,mp3 and MIDI, not sure if it records MP3 directly, but it plays them. Ek-50 also has a real nice control panel and Bass Inversion.