Video explanation
A distribution machine represents a 30-year loan. Moving along time reduces the balance and changes the allocation between interest and principal.
Interest follows balance
In a standard amortizing loan, interest depends on outstanding principal, so a higher balance generally means a larger interest share.
Principal share grows
With fixed rate and fixed principal-and-interest payments, falling balance reduces interest and increases the principal share.
Other payment components
Taxes, insurance and other components can raise payments beyond principal and interest. The video illustrates a mechanism, not a personal loan quote.