This is a black square button, which is formed by superimposing two squares. This emoticon is commonly used in the switch button of power supply, and is used to control the opening and closing of power supply.
Different platforms depict different icons. Most platforms depict two squares with different colors, the big square is black and the small square is white. The LG platform depicts a square with gradual gray. The emojidex platform depicts a black square, and two gray lines are added in the upper left corner to represent the luster of the graph. HTC platform depicts two gray squares with certain shadows. SoftBank platforms all depict or two black squares with shadow design and graphic luster. On the Docomo platform, two white lines with right angles are added to a gray square.
