According to halacha, if you have both bread and wine in front of you, the Hamotzi over the bread comes first.  However, our Sages ruled that on Shabbos, Kiddush on the wine should come first.  To avoid shaming the challahs, we cover them.

Now imagine, we are told to cover the lifeless challahs so as not to cause them embarrassment.  How much more so must one make sure not to embarrass or hurt the feelings of others.