This is a hard one to answer. The reason is that you are asked to distinguish between 2 schools of thought that are very close together. Not only that, but the characteristic you are looking for is not mentioned in either description.
Since semiotics brings in many more fields of study than does iconography, then I would go with iconography. This school of thought seems content just to find the symbols according to its description. What is done with them is mentioned in the other school but is not elaborated upon.
My answer would be iconography.
<u>Explanation</u>:
It could be observed that the scene<em> portrays animals eating the corpses of humans; </em>thereby <u>depicting how in reality animals are oppressed and even killed by humans </u>in the Wheel of Life.
Movement. It is one of the Principles of Art.
Movement is a principle of design found in an artwork wherein its usage is to give the sensation of action by creating the look and feel of an action within the artwork. The movement found within the artwork will guide the viewer's eye to see the artwork as a whole and not by its pieces.
Other Principles of Art are Rhythm, Balance, Emphasis, Proportion, Gradation, Harmony, and Variety.