Uranus means to be in the rhythms of the moment. Uranus forgets the past and future and wants to be right here and now. Jupiter likes to grow like a balloon. Uranus square Jupiter in the composite chart means that the couple are positive with each other, they are happy, bubbly and lively.
Venus means beauty in Astrology. It is your attraction to what is beautiful. Pluto is compulsive, irrational and it is your obsession. So Venus square Pluto in the Composite chart means the couple are irrationally drawn to beauty. A tendency to be devoted to each other.
Sun in astrology means you as a person. Your persona, life, the light of day, physical body, and your whole being in this earth. Venus is the attraction to beauty, love, and symmetry. Sun conjunct Venus in the Composite chart means the couple seek harmony, balance, understanding and they are really attracted to each other.