Screens are engineered to be more compelling than almost anything else a young child encounters. The rapid shifts, sounds, and visual stimulation keep the brain alerting system firing continuously, which feels intensely good. When you ask a little one to stop, you are asking them to leave a highly stimulating state for a much quieter one. The protest is real and physiological, not just preference.
You have two whole minutes to finish your spot, then we are going to do something great together. I will tell you what when the timer goes.