Q. Why is the Shofar kept covered on Rosh HaShanah until it is needed?
A. It is an expression of etiquette and respect. On Shabbat we keep the challot covered whilst we say the Kiddush over the wine, in order not to appear to slight the challot by keeping them waiting; similarly on Rosh HaShanah we keep the shofar covered until we are ready to use it.