On the last coach / bogey of passenger / express / goods train, there is mandatory rule of putting / attaching a plate written with words LV (indicating that it is last vehicle of that rake / consist). Hence, in this case, KYN WAG7 is leading loco and BL WAG7 happens to be LV (Last Vehicle). As LV Plate was not available, they have put red cloth (indicating it to be last vehicle)!