I have always felt like God has a plan for me and for the world, and that somehow they intermingle in some (albeit small :) way. In the early days of the church, these paths were not so relatively different in size. Those called to leadership positions in the church were often newly baptized members. This meant that as revelations were received by Joseph Smith to guide and direct the church, general principles had to be taught again and again, and these instructions were addressed both specifically to these individuals and to the church as a whole.

These revelations relevant to the church as a whole were gathered, edited and eventually published as "The Doctrine and Covenants of the Church of Jesus Christ of Latter-Day Saints." Some sections (as the chapters are called), such as 8, 9, and 25, contain portions addressed to specific individuals, while others like section 20 were information for the whole church.

A 'patriarchal blessing,' on the other hand, is rather amazing. Whether it was Israel blessing his sons as to their futures and progeny, Lehi blessing his children, or a man ordained to this duty in modern times (called a 'patriarch'), He has seen fit to bestow power and authority upon certain men so that they may pronounce the blessings He has prepared for individuals upon their heads. This always includes a declaration of one's 'lineage,' which is the tribe of Israel one is either descended from or adopted into. This carries a weight primarily because the tribe of Ephraim was charged with spreading the Good News of Jesus Christ's suffering, death, and resurrection to the entire world. (Other duties and blessings specific to these tribes are found throughout the Old Testament.) Other common points are warnings about weaknesses, promises of blessings (always conditional on obedience to God), and 'big picture' perspective on life.

Section 25 is, in essence, a patriarchal blessing. (http://scriptures.lds.org/en/dc/25, note the explanatory heading) Principles, such as in v.15's 'keep the commandments and great blessings will come' are very general. Also, v. 12 is a very general principle. This contrasts with vv. 6, 9 and 11 which are very specific to the recipient. Section 25 also differs in one major aspect: it is holy writ unto the world. If you receive a patriarchal blessing, it is holy writ to you, but not binding on the church. Also, the Lord gives each of us the ability to understand what revelations we receive mean, and this can change over time. For example, Emma, Section 25's recipient, may have reflected on v. 15 often for encouragement. She probably understood a 'crown of righteousness' as pertaining to the joy of going to heaven early on, but as the doctrines regarding the state of the righteous in heaven were revealed her vision of the promise must have expanded exponentially.