Piece of paper is folded and punched as shown below in the question figures.…

Concept: When a folded sheet of paper is punched and then unfolded, every fold line acts as a mirror line: each hole punched through the folded layers reflects across that crease as the fold is opened, so undoing the folds one at a time (last fold first) doubles the hole count at every step, provided no hole lies exactly on a crease.

Application: Here the square sheet is first folded in half along a vertical centre line to form a rectangle, and the rectangle is then folded along its diagonal to form a triangle; two holes are punched through this folded triangle, as shown:

1. Undo the diagonal fold first (the last fold made): each of the 2 punched holes reflects across the diagonal crease, adding one mirror-image hole for each, so the rectangle shows 4 holes in total.

2. Undo the vertical fold next: each of these 4 holes reflects across the vertical crease, adding one mirror-image hole for each, so the fully opened square shows 8 holes in total, symmetric about the vertical centre line.

Cross-check by counting: two punched holes, doubled by each of the two folds undone in reverse order, give 2 x 2 x 2 = 8 holes -- a hole near every corner of the square plus four more holes clustered together at its centre, mirrored left-to-right about the vertical crease.

So the correctly opened sheet is the one showing a hole close to each of the four corners together with a tight 2x2 cluster of four holes in the middle, all mirror-symmetric about the centre fold.