I’ve been dealing quite some time with trying to understand the specific archetype of your example, so, I would like to contribute with some thoughts. First, I would say both interpretations apply at the same time. In the example we are looking at the interface between the individual’s sense of individual purpose for this lifetime that translates into how the individual creatively actualizes self (Sun), and the linear and analytic thought function (Mercury). Thus, on one hand, the individual ‘instinctually initiates new experiences in order to explore new thoughts ideas, opinions and points of view in order to justify its life purpose’. The archetype implies the possibility that the sense of individual purpose may be linked with intellectual dynamics. The individual will instinctually project itself into its circumstantial reality in order to communicate with other people as a reflection of the individual’s own subjective sense of self. The individual may also project itself into the environment in order to give names and classifications to phenomena from the own subjective point of view, and can be very creative in producing thought/communication forms and very personal arrangements of reality at an intellectual level.
At same time, ‘the individual instinctually initiates new experiences in order to develop a new life purpose which serves to justify his thoughts, ideas, opinions and point of view’. The archetype implies that the individual will be collecting information that, in time, will serve not only to justify, but also to linearly understand what the personal purpose is, or to adjust or discriminate this personal purpose, and the specific ways to creatively actualize this sense of purpose and special destiny. Sometimes this will imply the need to create crises (because Mercury ‘carries’ the energy of both Gemini and Virgo) on an instinctual spontaneous basis serving to induce the need for adjustment or discrimination of the personal purpose and the ways in which this needs to be actualized. Thus, both archetypes –Sun and Mercury - integrate in both ways. AIso, I would say that there will be variations and one way may be more relevant than the other in each individual case, depending on the signature of the birthchart and the main evolutionary axis, in relation with the evolutionary condition of the individual.
Hope this serves, and look forward to read what others post.