The idiom "giant in action, dwarf in language" is used to describe the inconsistency between words and deeds, or the inconsistency between words and deeds. Specifically, it means talking more and doing less. In other words, this man is full of momentum, determination and ambition, but in fact he is mediocre and has nothing to do. This idiom can be used to describe those who are bluffing and ineffective, and satirize them as people who just "break their word".