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 ▢ ▢ ▢ X

Distractor grid 1:

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

Distractor grid 2:

X ▢ ▢ ▢ X
X ▢ ▢ ▢ 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: This grid has a diagonal pattern of "X" marks starting from the top left and going to the bottom right, with empty cells in between.
assistant
Expression: The target grid has a "T"-shaped pattern of filled cells in the center, with additional filled cells in the top left and bottom right corners. It differs from Distractor 1, which has a solid block of filled cells in the center, and Distractor 2, which has a similar "T"-shape but with the top and bottom rows completed.
assistant