Domino

The board contains 27 dominoes. By systematically checking all possible dominoes from a double-six set, the 0-5 domino is not present among the visible dominoes...

Checking the dominoes against the complete double-six set, every double appears on the board except the 3-3 domino, which is absent.

The pip counts in this low-resolution image are hard to read reliably, so this is a best guess. I could not confidently confirm that the 4-6 domino is absent fr...

The board contains 27 dominoes. Examining all dominoes with a blank (0) half: 0-0, 0-1, 0-2, 0-3, 0-5, and 0-6 all appear on the board, but the 0-4 domino never...

Reading the 27 visible dominoes and normalizing each tile to an unordered pair, the board contains every double-six combination except 0-6. The only blank-plus-...

The board shows 27 dominoes. Enumerating every visible domino and checking all 28 combinations of the double-six set (0-0 through 6-6) in ascending order, every...

The blank halves appear paired with 0, 1, 3, 4, 5, and 6, but never with 2. Thus the 0-2 domino is missing.