[mgdlbp]

I think the idea is that the shipping time will be too short to allow freezing the tampered-with phone into a new block of ice of such size, and the scratches prevent it from being substituted by a pre-frozen replacement.

Might be countered by supercooled water if the crystallization can be made to look natural.

[ebeip90]

^ This

Supercooled water was something I thought of later, but I didn't think about the presence / lack of bubbles from normal freezing.