This unusual conversion of a 40 foot boxcar was seen in GO Transit's Willowbrook Yard on several occasions in the early 1990's. By then it could have been retired, like GO's stored APCU's, APU's and GP40M-2's.
It is painted to resemble one end of GO Transit 2+level coach, with windows, etc. 
IIRC someone told me it had been used for teaching conductors GO train door control operation. 
If so, one feature it lacks is an openable window in the conductor's original upper-level location.