Frenzy (1972) Easter Egg - Body Floats By

After the opening credits director Hitchcock in black suit with black bowler; stands in a small crowd listening to a campaigning politician make an impassioned speech about cleaning up the river while they stand on a river bank.
A strangled woman with a necktie around her neck floats by in the river. In the next scene the body is fished out of the polluted river. We see the back of the crowd and the back of Hitch.