Only real use I can imagine for these is wildland firefighting. I figure it's supposed to be used for reducing risk to firefighters when the time comes to create backfires in the path of a wildfire. Can sit in the truck with a remote control and send the robot dog to walk a few miles setting a line of fire.
Checked company website. Looks like they also market it for agricultural use and deicing. From a childhood spent farming, I can see how it might be useful in agriculture. Every year farmers need to set fires and burn what remains of fields after harvesting crops like grain. A few times over the years I witnessed people get themselves in dangerous situations (trapped in the middle of a fire or their pickup truck trapped) after the fire spreads in unexpected directions. Being able to stand back at the edge of the field and remotely set the fires could be useful. The risk of burning up a $9,000 robot dog is a lot cheaper than a human life or $60,000 pickup truck.