A hand holding scissors about to cut a bag strap.

The video demonstrates three common mistakes to avoid when choosing a sling bag. It starts with a close-up of a person's back, showing a bag strap being cut, then transitions to close-ups of bag straps and buckles. It then shows various sling bags being worn by different people in different settings (mall, outdoors, indoors). The video highlights issues like bad strap and weight distribution, bags being too small or too large, and poor security features. Finally, it showcases a well-fitting bag that stays flat against the body and has good security features, suggesting it's the ideal choice.