Looping will enable your design to continuously play after it's timeline would have ended starting again from the beginning. Usually this can cause some confusion if you're planning on uploading your work onto GoogleAds, as it can enable a blocker if the entire duration goes over 30 seconds. Considering your banner has a total duration of 10 seconds, a loop no greater than 2 would have to be implemented, otherwise the total duration will exceed the limit imposed by most marketing platforms.

To prevent your banner from looping, you would need to either set the loop count to "once" or simply check the "stop slide" function found in the last slide of your design.