Better to check it for real.
On a car, jack up one front tire. Select neutral. Turn the wheel (the one in the air) by hand and you will clearly feel if there is a LSD in there. It wil be very easy to turn it slowly, but impossible to speed it up.
If the box has been separated form the car, one can just look inside from the driveshaft hole and see if there's a LSD or standard differential.