That's what we call flood cleaning carpet. The carpet cleaner in the video has soaked the carpet to the point of flooding the carpet. They have literally flooded the area with so much water that it's like stepping into a puddle. They are using a truck mounted carpet cleaning system with hot water extraction to remove the caked on dirt in the traffic lane of this place of business.
I do not recommend this type of cleaning because the carpet is going to take days to dry out and the adhesive holding the carpet in place is likely damaged in the process of cleaning.
I clean commercial carpets all the time here in Tampa FL using a much drier method of cleaning. It's similar to hot water extraction but only using a small fraction of the water used by most steam cleaners. Cleaning traffic lanes can be grueling but it can be done without soaking the carpet and putting it at risk. Consider using a drier option to ensure a clean and healthy carpet.