Halakhah for Isaiah 3:16

You should not walk with an upright [haughty] posture and an outstretched neck, as it is said: "And they walked with outstretched necks."¹³Isaiah 3:16. Nevertheless, you should not bend your head excessively, but only moderately so that you will be able to see anyone approaching you and also see where you are walking. (Rabbeinu Yonah in Sefer Hayirah). From the way a person walks we can tell if he is wise and intelligent, or if he is a fool and a boor. Thus said King Solomon in his wisdom: "Also in the manner that a fool walks his heart fails him, and he announces to all his foolishness,"¹⁴Koheles 10:3. thereby informing everyone that he is a fool.