A request for proposal for a specific program may require the company to review the bids to not only examine their feasibility but also the health of the bidding company and the ability of the bidder to actually do what is proposed.
The most obvious reason for using spatial imagery in metaphors is that the language of the primary processes (e.g., dreams) is spatial imagery. This can explain everything, but is trivial: it is always true, and you cannot make meaningful distinctions with it in a text or in changing contexts.
Guided imagery is simply the use of one's imagination to promote mental and physical health. It can be self-directed, where the individual puts himself into a relaxed state and creates his own images, or directed by others.