What activity do you see here?
The person in the picture above is busy marking the next stripe to be mowed in the grass pitch. International football governing bodies like FIFA and UEFA, as well as most FAs, strictly govern mowing patterns and stripes, as these act as a visual support to assistant referees in establishing whether a player is standing off-side. Guidelines of these football authorities will dictate the required width up to the specific centimetre.
While robotic mowers have the capacity to autonomously mow the grass pitch, it is strongly advised to groundsmen responsible for professional stadium fields to still do the final mowing session prior to the match manually. Despite the latest generation of autonomous mowing robots having the capacity to cut the grass in a certain pattern, their accuracy has a tolerance of several centimetres. With the football governing bodies prescribing the required width exactly, they leave no space for such toleration.