You need to understand how shapes and their perspectives work in space, as well as image composition in terms of what you want to give protagonism to. If you place the tail at the same level and size, side by side with the upper body/trunk, you're telling the viewer to also pay attention to it, which is not the intention unless it plays a fundamental role — for example, in a confrontation. Maybe in a strange scenario where the tail comes to life and wants to fight against the mermaid. | Artwod Feedback