Label: toy block labels. Not AES output. No cipher program was run.
ECB, under one key, assigns one ciphertext label to each plaintext block.
The same plaintext label keeps the same ciphertext label.

Worked plaintext blocks: AA AA BB
Worked ciphertext labels: XX XX YY
XX appears twice.

Activity plaintext blocks: QQ RR QQ
Activity ciphertext labels: 11 22 11
Predicted: the label 11 appears twice.