Extra precautions have been taken for iPhone 15 boxes that give retail employees and buyers a new way to verify the device is real — but you'll need a UV light.
Makes counterfeiting just a bit more difficult. Like when money started having this. Where I lived getting one of these uv flashlight to check notes was very common back then.
A ”smart” thief will just garbage hunt through the bins of retailers, find legitimate boxes, fill those legitimate boxes with junk (or a rock), then reapply the fastening tapes.
A potential victim won’t look twice at an unopened box. They will be blinded by the whatever % off from retail cost.
It’s a nice security feature but easily defeated.
As a buyer of used phones I always open the box, check the contents, and cross check the IMEI for any carrier locks. Also check if it’s iCloud locked.