“He shakes his fist.” It is a very common human jesture to shake your fist at something or someone in anger and defiance.
“Daughter Zion.” The Hebrew is idiomatic for Zion itself, i.e., Jerusalem (see commentary on Isa. 1:8). Describing Zion as a daughter can have the connotation of someone that is beloved, but more often, and certainly here, it has the connotation of one who is like a daughter in that culture: vulnerable, in need of support and protection. Zion would be smitten by the Assyrians (Isa. 10:22-23), but God would eventually vindicate her. However, we know from history that she would not be grateful for God’s deliverance, but would turn against Him and be carried into captivity by the Babylonians.