Here "image" does not mean a representation of something that is visible. Instead, "image" here means that by knowing the Son, we learn what God the Father is like. (See: [[rc://en/ta/man/translate/figs-metaphor]])
"The Son is the firstborn." The expression "firstborn Son" does not refer to Jesus' birth in Bethlehem. Instead, it refers to the Son's position as the eternal Son of God the Father. In this sense, "firstborn" is a metaphor meaning "most important." Jesus is the most important and the unique "Son" of God. He is God. The word "Son" shows Jesus' intimate relationship with the Father. That relationship cannot be understood until and unless you use your language's words for "son" and "father." (See: [[rc://en/ta/man/translate/figs-metaphor]])