A piece (often a bad bishop, but in your second example a queen) which is doing nothing more than protecting a few squares is often called a big pawn. To be honest, I don't find your second example a real case of a 'big pawn', because the queen can easily move away and do something useful. And, as Dag Oskar Madsen mentions, in the first example the *pawn breakthrough* is big, not the pawn itself.