Indoor ornamental plants have become increasingly important in modern urban environments due to their aesthetic, environmental, and psychological benefits. Their growth and spatial development are highly influenced by environmental factors, particularly light intensity and irrigation levels. This review synthesizes current scientific knowledge regarding the physiological, morphological, and developmental responses of indoor ornamental plants to varying light and water conditions. Evidence from recent studies indicates that both insufficient and excessive light or water can significantly impair plant performance, while optimal combinations promote leaf expansion, biomass accumulation, and lateral spread. Species-specific responses, light–water interactions, and physiological mechanisms underlying growth regulation are highlighted. The review emphasizes practical applications for indoor horticultural management and identifies gaps in current knowledge, providing directions for future research.