Is this ok?

Today I came out of the office building my lactation room is in and went to go out the door and this is one of them doors that has a small window in it. Earlier when I went to pump everything was normal. This time I went to leave and meet my fiance and someone had covered up the window so no one could see inside the office that way. This office building my room is in has all men in it which is somewhat uncomfortable to begin with 3 of the 5 men I'm not threatened by the other two can creep me out. Is this ok for them to do start blocking windows so people can't see inside?