You are given three grids, where each of them is 5 by 5 in size.
Grids have empty cells marked with "▢" and filled cells marked with "X".
Your task is to generate a referring expression that best describes the target grid while distinguishing it from the two other distractor grids.
The first grid is the target grid, and the following two grids are the distractors.

Target grid:

▢ ▢ ▢ ▢ ▢
▢ ▢ ▢ ▢ ▢
▢ X ▢ X ▢
X X X ▢ X
X X X ▢ X

Distractor grid 1:

X ▢ X ▢ X
▢ ▢ ▢ X X
▢ ▢ ▢ X ▢
X ▢ X ▢ ▢
▢ X X ▢ ▢

Distractor grid 2:

▢ X X ▢ ▢
X ▢ ▢ X ▢
X ▢ ▢ ▢ ▢
X X ▢ ▢ ▢
X X ▢ ▢ X

Instruction: Describe the target grid.
Generate the referring expression starting with the tag "Expression: " for the given target grid. Omit any other text.
Expression: The grid features a row of three filled cells in the fourth row, with the third and fifth cells also filled in the third row, creating a distinct pattern of filled cells that is not present in the other grids.
assistant
Expression:

The target grid has a unique X placement in the second row, where it is directly below the first X in the first row.
assistant