How did Scipio Africanus use several days of skirmishing to deceive the Carthaginian commanders before Ilipa?

Before the Battle of Ilipa, Scipio Africanus used several days of light, indecisive skirmishing to establish a predictable pattern of behavior. Each day, both the Roman and Carthaginian forces would form up for battle but retire before fully engaging, effectively lulling the Carthaginian commanders, Hasdrubal Gisco and Mago, into a sense of routine.12

Once this pattern was established, Scipio dramatically broke the routine on the day of the battle. He ordered his troops to be fed and armed before daybreak and launched an attack on the Carthaginian outposts at dawn. This forced the Carthaginian army to rush onto the battlefield without breakfast, leaving them vulnerable to fatigue and hunger as the day progressed. Taking advantage of their haste, Scipio deployed his troops in a new order, positioning his strongest units against the weakest parts of the Carthaginian line to secure a decisive victory.12