That means by religious law no non-kosher food is allowed under its roof during that week. To store or bring in such food would violate the state of the whole hotel. It does not work that way in reverse. Making Kosher food in a non-kosher building does not spoil anything for the other, non-Kosher diners.
Lebanese protesters storm environment ministry amid trash crisis (AP)
from the article: No bread for Obama: Presidential fare to be kosher for Passover