Answer
This is a hands-on demonstration. The water is deflected toward the charged comb.
Work Step by Step
The negatively charged comb induces a complementary positive charge on the closer side of the stream of water (i.e., it polarizes the water) . The charge on the comb then attracts the oppositely-charged stream of water.
You'll notice that the charged comb attracts small dust and paper particles too.
This is discussed on page 416 and shown in Figures 22.12 and 22.13.