The apothecary diaries manga and light novel differ in several ways. Firstly, the format itself affects the storytelling. The light novel allows for long, descriptive passages that build the world in a detailed manner. In contrast, the manga uses panels and visual cues. The light novel might be better for those who enjoy detailed internal monologues of characters like Maomao, while the manga is great for those who prefer a more immediate and visual experience. Additionally, the adaptation process from light novel to manga may lead to some changes in the sequence of events or the emphasis on certain story elements for the sake of better visual flow.
Well, one major difference is the art style in the manga. It gives a visual representation of the characters and settings that the light novel leaves to the reader's imagination. Also, the pacing can be different. The manga might have to condense some parts compared to the more detailed descriptions in the light novel.