Still using ropes instead of standardized harness for fixing payloads onto quadrupled robots.
To be fair, the robot dogs are fairly small, primitive and exploratory in nature at present. They're hardly bespoke or hardened designs, and not practical for actual combat as they are. How they secure a container on the robot dog is a relatively small issue in that context.
It's the equivalent of Phantom quadcopter drones dropping hand grenades during the mid 2010s in the middle east, which is... perfectly fine as initial tech demonstration.