Every droid has a series of commands that it can be 'taught' or 'programmed'. If you have dealt with creatures as a Creature Handler, this will be very familiar to you. Once you have called a droid from your Datapad, you can click on the droid's Radial Menu and select Program. A list of commands will appear in the Teach Pet Commands window. Once you select a command and press the Train button, the droid will say "?" to you in Spatial; the next thing you say either in Spatial or using /tellpet, the droid will now use as activation for that command, and will confirm that it has been programmed by then saying "!" to you in Spatial.