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 target grid has a top row fully filled with "X" except for the last cell, and the third row has "X" in the first, third, and fifth cells. The bottom row has "X" in the last two cells, and the fourth row has a single "X" in the last cell.
assistant
Expression: The target grid features a diagonal pattern of X's and ▢'s, with X's forming a diagonal line from the top-left to the bottom-right corner, and ▢'s filling the remaining spaces. The X's are concentrated in the top-left and bottom-right corners, while the middle section is filled with ▢'s.
assistant