QQ2 · 2026-10-21

QQ2: Identical Faces, Different Physical Cards

Matching pictures can belong to different physical tiles. Use simple identifiers to track movements without confusing identity with appearance.

Two picture tiles both show a mango. On their backs, the organiser has written A and B so their movements can be tracked.

The matching game treats the pictures as equivalent. The movement record still distinguishes which physical tile was placed in each square.

An unchanged picture can hide a swap

Swap A and B. The face-up board looks unchanged, although the physical positions of the labelled tiles have reversed.

That observation explains why appearance alone may not reveal whether a swap occurred. The hidden identifiers carry information the pictures do not.

For the ordinary picture task, the swap may make no difference to the answer. For an exact movement-replay task, it matters.

State which task you are checking before calling two arrangements “the same”. Same pictures and same physical placement are different meanings.

Add a third tile with a different picture. Swapping it with a mango changes both appearance and physical identity positions.

Photograph the fronts for the picture record and note the back labels separately for the movement record. Each record serves its own purpose.

Players can now explain why one swap was invisible from the front while the other was obvious. They have identified the relevant information.

The QQ2 tile exercise separates matching from tracking. Equal-looking pieces can be interchangeable for one rule and distinct for another.