Why do we cover the challah (braided loaf of bread) on Friday night, Sabbath morning, and on holidays during the Kiddush?
1. As a reminder of the manna in the wilderness that fell with an extra protective coating of dew.
2. So that the "feelings" of the bread not be hurt while all the attention is focused on the wine during the kiddush. In the standard priority in which food is eaten, bread is always first, based on the order of foods as presented in Deuteronomy 8:8.
However, since kiddush over wine is recited first on the Sabbath in order to sanctify the day, the bread is covered so as not to "slight its feelings" by skipping over it and stripping it of its exalted status.
This ritual teaches sensitivity to the "feelings" even of an inanimate object. Of course its ultimate purpose is to teach us to be more sensitive when we interface with our friends and acquaintances.
See also: When Inanimate Objects Have 'Feelings'