Figure 3-12 is likely classified as a sculpture because it is a three-dimensional artwork that is carved or modeled in relief. Relief sculpture is a type of sculpture in which figures or designs are carved into a flat surface, with the background left at the original surface level. In the case of Figure 3-12, the figures and designs are carved into a flat surface but are raised in various degrees of depth to create a sense of depth and dimensionality.
Space is suggested in this relief through the use of depth and overlapping forms. The figures and designs are carved in various degrees of depth, with some forms appearing more recessed than others. This creates a sense of space and distance between the different elements of the relief. Additionally, the forms overlap each other, with some forms appearing to be in front of or behind others, which also contributes to the illusion of space within the artwork.
Overall, while Figure 3-12 may be intended to be viewed from the front only, it is still classified as a sculpture because it is a three-dimensional artwork that is carved in relief. The use of depth and overlapping forms in the relief suggests a sense of space and dimensionality within the artwork.