The description you provided indicates that there are uncharged particles bouncing around within a square, and the presence of arrows pointing outwards from the edges of the circles suggests that these particles are moving freely and potentially moving away from each other.
Based on this information, the state of matter most likely represented in the image is Gas. In gases, particles are widely spaced, move freely, and have high kinetic energy, allowing them to bounce around and fill the available space. In contrast, solids have tightly packed particles in fixed positions, liquids have closely packed particles that can slide past one another, and plasma consists of charged particles.