Photos can show core-tank size, cooling configuration (radiators, fans, pumps), bushing types and positions, OLTC compartments, and accessory layouts. They reveal whether the transformer is single-phase or three-phase, its approximate voltage level (from bushing size and spacing), and how it is integrated into substation buswork. Visual cues such as conservators, nitrogen blankets, and fire barriers provide insight into insulation and safety concepts. While not a substitute for drawings, images help understand overall construction and application.