"toph" is short for the term "top-heavy." In the context of a porn video, it refers to a female performer who has a larger chest or breasts than the average person. The term might be used by viewers to describe their preference for women with fuller, more ample breasts. This tag can be associated with other terms such as "big tits" or "large breasts." It's important to note that this description is for an adult audience familiar with adult content and may not reflect the preferences of all individuals.