Usually one boils seeds and any other dried material one adds to cheese. Only a little bit of water is used. This sterilizes the seeds and the flavored water can be added to the cheese milk. The boiled seeds could be ground into a paste that was also added to the milk. Obviously, the seeds on the outside of the cheese ball were not ground. If they were added just prior to cutting the cheese they likely would not need to be sterilized - otherwise they should be as they might carry unwanted yeasts, molds, etc onto the cheese. Judging from the photo I'd say they were added about the time the cheese was packaged for shipment and consumption. The color is dark enough to indicate that they might have been toasted as raw mustard seeds are light yellow in color. This would also sterilize them.
By the way, welcome to the Forum. It is a neat place to hang out. A lot of people that post make some imaginative cheeses. The cool thing is that you can do searches and learn some interesting ideas. Why don't you try making this cheese. Keep notes and post your recipe with pictures of the results both after making the cheese and aging it. This is generally how one earns cheeses (thumbs up).