It's not such an easy question, Ivan, even for a native speaker. The word "open" seems to be designed to suggest qualities rather than describe literal attributes: it works by connotation, rather than denotation. Applied to a perfume, I associate "open" with honesty and simplicity, as when you describe a person as having an open nature. "Sparkling" suggest brightness, energy, something invigorating (I'm sure it doesn't mean that the eau de toilette is literally fizzy!). So I think it's meant to imply that the perfume is uncomplicated and fresh. It's trying to capture a feeling. Some combination of the words listed above might express what is involved.