It lit. means "to obtain 3 cm and advance 1/3 meter". It describes someone who’s so greedy that if you give them a little bit, they'll come right back and ask for much more. It indicates big greediness.
to impersonate somebody but gain the opposite of the desired effect
It lit. means "Dongshi imitates and knits the brows". It refers to a story of an ugly woman who was trying to imitate a beautiful woman praised by everyone. She tried to imitate the beautiful woman, but nobody looked at her.
望洋兴叹
望洋: "to gaze at the air"/ 兴叹: "to lament", "to have a sigh"