Symbolic analysis: The basic elements are the tree, path, and mist of darkness. The tree must be seen as a goal, else there is little reason for beginning on the path. Therefore the mists of darkness, representing the veil on the one hand and the temptations of the world on the other, do not obscure the vision of the tree (at least at first). The path is also marked and known.
The symbolic setup for the imagery is that the end of our existence is known to us, and both the reward and the way are open and visible to us. Neither of these things are hidden. It is not in the purposes of God to obscure the goal nor the way. The mists of darkness arise after we are on the path.
Where the mists of darkness represent the veil, the beginning of the path is in the premortal life. Where the mists of darkness represent the temptations of this life, the beginning of the path is when we find it during this earth life. In this latter mode, the vision is descriptive of the process of conversion.
It would seem that the two ways of looking at the mists of darkness provide quite different meanings for the tree of life vision. That is essentially correct, but certainly not beyond the power of symbolisms to evoke a multiplicity of meanings. It is the very power of symbols to evoke multiple meanings and contexts simultaneously that makes them powerful.