Many times there is cake, cookies or various other foods out on the table during Kiddush. Is it necessary to cover them (as I sometimes see people do)? Would it make a difference if the cake is going to be eaten in lieu of Grape Juice?
The reason of the "shame" of the challos, applies to mezonos as well, since ordinarily the blessing of mezonos is recited before the blessing of ha-gafen. Indeed, some poskim rule that cakes and pastries should be covered during the recital of the morning Kiddush.(Kitzur Shulchan Aruch 55:5; Teshuvos Levushei Mordechai O.C. kamma, 46. Even according to this view, however, only the person making Kiddush [and others who are partaking of the wine] needs to cover his mezonos items. All other participants do not need to cover their mezonos, since they are not "shaming" the mezonos by listening to Kiddush; Harav S.Z. Auerbach (Shemiras Shabbos K'hilchasah 47, note 125).
But not all poskim agree. Eishel Avraham Orach Chaim 182 holds that mezonos items do not need to be covered during Kiddush because only challos - which can be used for Kiddush and are being bypassed in favor of wine - are being "shamed." Mezonos items, however, are generally not eligible to have Kiddush recited over them, so they cannot be "shamed" by the wine taking precedence over them.(Ta'amei ha-Minhagim, 365, Kuntress Acharon; Az Nidberu 2:)
Hacham Ovadia writes in Hazon Ovadia that one should cover the cake as well before Kidush.