Flashing, blinking, twinkling, animated or moving signs of any type shall be prohibited. A sign may electronically change from one message to another message, provided that the message does not flash and stays on for a duration of at least 25 seconds. In addition, flashing lights visible from a street shall not be used to attract attention to a business. This restriction specifically includes window signs but does not prohibit seasonal Christmas lighting or displays that comply with § 703.