Although standard banners allows for up to 30 seconds of loops. Some creatives require a set amount of loops for a shorter banner creative.

For example, a banner set that is a short 5 second total creative may only need to loop 3 times rather than the defaulted 6.

Instead of having to duplicate frames multiple times to manually set the loops and duration, it would be beneficial to set "number of loops" similar to making a manual GIF.