Goose feather coat: refers to girls (because clothes made of goose feather are usually bright yellow, soft and delicate, suitable for girls to wear, which may be borrowed here to refer to girls)
Jinse: refers to a beautifully decorated musical instrument, which is a kind of plucked musical instrument and generally has 25 strings. After Li Shangyin's "Jinse", ancient literati used to use the years of life as a metaphor, which was called the years of life, and there was also a feeling of seeing things and thinking about people and lamenting the passage of time.
So the meaning of the whole sentence is roughly: an innocent girl (this girl may refer to myself or others, depending on the specific context. ), but after all, I am the only one looking at gorgeous Arthur and looking forward to the years.
It may not be accurate, but as far as I understand it, it means something like this.