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 p

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.