The staff are friendly enough. position by way of what you could call the 'height rule'. In any social encounter the social superiors head must always be higher than the social inferiors head. The lower you stoop means you show more respect to the person you meet or are passing by.
In a school situation this is more evident and it can be quite an eye opener to watch. As a white person I am seen quite high up the hierarchy tree. This means that other teachers will stoop as they pass me even if they are much older than me. (Thai people respect their elders like we do). I do find this a bit unnerving so I tend to stoop too, thus giving them as much respect back.
The Head Teacher is at the top of the hierarchy in the school. If she is sitting at her desk, staff who want to talk to her or give her something will sit on the floor beside her. It is an amazing thing to see, especially when seeing more mature teaches sitting on the floor showing great respect.