To protect against excess light, photosynthetic organisms activate a variety of defense mechanisms to prevent photodamage. One such strategy involves the expression of a specific gene isoform called Lhcb8. In this study, we employed a structure-function approach to explore the physiological and structural effects of accumulating this rarely expressed antenna protein isoform. Our results show that expressing Lhcb8 leads to a reduction in size and a looser organization of the photosystem II supercomplex, without compromising its quantum efficiency. These findings broaden the toolkit for engineering enhanced plant photosynthesis.