No person shall place any merchandise or obstruction of any kind upon any street or sidewalk within the city for the purpose of advertising, display or sale. Wherever a business house is constructed and maintained close to the property line between any public street or sidewalk and such business property and the owner of the property has caused the space between the city sidewalk line and the front of such building to be cemented or otherwise improved in such manner as to cause the same to appear to be a part of the city sidewalk, and such part so improved by such owner is constantly used by pedestrians as a part of the sidewalk, no owner of such property, his or her lessee, tenant, agent or any other person shall construct or maintain wholly or partly on such ground between the city sidewalk line and the front of such building any structure for the sale, advertising or display of merchandise which is constructed in whole or in part of glass or dangerous materials.