It's easy to talk the talk and give advice on love, careers or even recycling on how things should be done. But, the person giving the advice does not act in a way that agrees with the advice they are giving. The proverb implies that a person should back up their talking with action.
Beware of the naked man who offers you clothes is a proverb used to call out hypocrites; people who are single but give advice on how to have a happy marriage, a person who is overweight supplying dieting tips, environmentalists who do not recycle, people on social media who want to show you how to become rich when they are poor, and politicians who send their children to private school while making speeches on the virtues of public school.