In the context of physics or chemistry, homogeneous refers to mixtures of substances in the same phase. Similarly, heterogeneous would refer to substances in different phases. The phases can be solid, liquid or gas.
Although its not clear from the image (and no context is given), it appears like a bunch of balls in a container. If we assume all the spheres to be solids, then this is a case of homogeneous mixture.
Kindly note that, homogeneous or heterogeneous also refers to distribution of properties and without appropriate context it is very difficult to determine the exact use of these terms. If we use this definition (uniformity of properties as a sign of homogeneity), each row contains two balls of each color and thus represents a homogeneous case.
hope this helps.
It can be homogeneous if it represents atoms in a solid state of matter as shown by their close conformity. But because of the 2 different colors, it can represent a heterogeneous object by relating to two different types of atoms.