The way things align between two people describes how those two people align in their interpersonal relationship.
Having Mercury well aligned between two people, for example, signifies that these people can communicate effectively, as a result of the way they both think. For example, having Mercury literally aligned (at the same zodiac degree) between two people indicates that they think alike, their intellect operates in similar ways, therefore they can communicate effectively.
As with every astrological symbol, it is just one out of a soup of many things you have to consider.
As another example, having one person’s Jupiter align near the same degree as another person’s Mars means that the two people would inspire (Mars) morality (Jupiter) in each other, they would inspire one another to learn and grow (Jupiter). Especially, the person with Jupiter would be the guide for the aspirations and ambitions of the person with Mars.
Another example, having one person’s Jupiter align near the same degree as another person’s Venus – this means that the two people help one another gain knowledge (both Jupiter and Venus are learned brahmana), the two people will benefit one another, and like each other’s advice, guidance, wisdom, etc. Especially, the person with Venus would like and appreciate the wisdom, guidance, etc of the person with Jupiter.
A last example, if one person’s moon is near the same degree as another person’s ascendant it indicates that the two can intuitively understand one other’s opinions, desires and feelings. The subjectivity (Moon) of the person with the Moon at the particular degree, is tangible (Ascendant), not elusive of mysterious, to the person with the Ascendant at that degree.