According to the situation described by the landlord, the interview was with a listed company. If the company is large in scale and has been established for a long time, the internal process should be able to refer to the complete rules and regulations, which will be time-consuming. Moreover, as a staff member of the company, before hiring, apart from analyzing whether the landlord's situation is suitable for the company, there are many other work related to the landlord to do, but the landlord can't see it. These also take time.
If you are really anxious, you can politely call the other person and say, "I am very interested in this position. I want to know how it is going?" Anyway, it's Monday. I haven't left work yet, have I? The frequency should not be too high.
Good luck. Because the landlord is at work, this situation will ensure that there are no mistakes in the work at hand and do less other things.