This is my second and probably last report on this topic:
The "Coin" music video:
The gambling theme is based on the 2006 South Korean movie "Tazza: The High Rollers (타짜, The War of Flowers)" which was a major hit that was continued in at least two other films and a TV show.
About the Spanish style influences, the linkage comes from a single line in the song (actually in the rap) where her gambling is compared to a bull fight. But I do not know if the connection with bull fighting comes from the movie. I think that it is probably a line in the movie, but I have not seen the movie, so I cannot verify it. The movie was released on DVD in North America, so maybe someone will report on it later.
In the music video most of the extras wear animal face masks, so I thought there might be some "bovine" masks. Mostly I saw other animals, like foxes or wolves. I only saw one mask that might have been a bull or a cow, but it might have been something else, so might have been a deliberate avoidance of bovine masks, or there was another theme in the video that I have not figured out yet. So either the bull fight style influence seems to be limited to IU's clothing, both as a story character and as a dancer, or it was simple not carried through.
Notably, her final opponent in the music video was Kim Yun Seok who played a key role in the "High Rollers" movie and reprised the role in the 2nd "Tazza" movie "Tazza: The Hidden Card", so he is strongly associated with the movies. She is probably proud of that cameo.
As for IU wearing "men's fashions", I think it was just her attempt to "toughen-up" the character. I do not think there was anything further linked to movie and I don't think she will be following up with a Kate Hepburn look beyond promoting this song, so not a "fashion statement" but just a part of her song promoting.
About the Brown Pants in "IU's Palette" episode 5:
I realized later that this is probably completely unrelated. I have seen "behind the scenes" videos enough to know that in South Korea, some of the large studio sets are nothing more than big buildings, with very little insulation or heating. This episode was probably recorded around mid-winter, and sometimes it is so cold that it is hard to hide breath condensation. SHINee members were all dressed in layers with jackets and sweaters under the jackets. The band also looks warmly dressed. So I suspect that IU was wearing baggy pants to hide the fact that she was wearing "long johns". It was probably that simple -- not a "fashion statement" but just "survival". As for the pants being mid-dark brown, it was probably just what was buyable in a hurry.
About her Brown Jacket for her "Sketchbook" appearance:
Nothing surprising here. The jacket is trimmed Spanish style coming from the "Coin" song she was promoting. I take the brown colour as a somewhat random matter. For video it records better than black, and that's about it.
About Beige:
After you mentioned it, I noticed that in "IU's Palette" episode 7 she was wearing "men's" shirt, tie and vest, in beige. This was part of her promoting the song, but I had to laugh at the beige.
Speaking of beige, I have been wearing khaki, beige, bone or white pants for over 30 years myself. I do this as a practical safety matter. When I am out walking at night it should be more visible than black or other dark colours, so drivers won't hit me. I used to get annoyed that the colours tended to change every time I had to buy new ones. Now? Meh.
As for SK as a fashion centre:
I have heard that, in SK news reports, but I do not know that it is that influential. I doubt if Japan pays that much attention to SK. Japan still tends to ignore the outside world. Then there is Hong Kong, the rest of the "water world" and China. I dunno. Yes, they see what's up in SK, but I think they are as influenced by other countries about as strongly.
Being a wearer of beige pants, you might take my fashion opinion as "suspect".
