It's very possible that her assistants helped her a lot, corrected some of her poses, etc.
If that is indeed true, it would be ironic because generally assistants are the
ones who learn from the mangaka they work under, as assistants are themselves aspiring mangakas hoping to get their debut.
If anything it should be Takeuchi correcting her assistants not the other way around.
Well i think she progressed during her manga publication and general panel composition or anatomy were A BIT better than in the begining, same for her color arts, some pieces were nice in Stars. But it seems she lost most of her progress after the series ended.
Her art was at it's best during the middle of the Dream arc. The Minako Dream Chapter is probably her best work (for once she was drawing backgrounds and the jungle scenery greatly adds depth to her work) while the next one, the Outers chapter, is probably one of her worst with characters just standing with their hair in the wind lol.
Her early 2000's style is more childish because it's easier to draw. It was CG but without all poor taste filters and textures that would come later.
And we are now to this horrible era with overused textures and clashing colors, stock pictures from backgrounds, cheap fire or bubbles effect... The olympics one was the absolute worst in my opinion (closely followed by Chibiusa/Hotaru from Chanel).
I really like the Cover Arts from the Shinsoban edition - what is really good about them is that the girls are very expressive and have some body language/good poses.
The Kanzenban covers, on the other hand - boring; awkward poses, messy colors, deadpan expressions...
Everything since the Olympic art she did has been extremely underwhelming when you take into account she's supposedly a veteran mangaka.
She hasn't even remotely touched a pen for years and it greatly shows.
Takeuchi has no idea what is anatomy or how to make composition.
When you analyze her work, she clearly doesn't and hasn't shown any will to learn how to.
She doesn't know much about anatomy and body language so what she does most of the time is have the character stand, with each arms in the opposite direction - rinse and repeat.
These 2 pictures are a very good example of nice fashion sense. Clothes don't seem to have been pasted (as paper dolls) on characters and are prettily drawn. One of Takeuchi's problem is that she is unable to draw some faces angles (like the characters on the left on your second picture, or the third one). So she can't give variety to her poses and her composition because it would mean drawing characters on weird angles and she doesn't even want to try.
If you look at Chibiusa's face on this Chanel art and rotate a little, you will notice her face is absolutely ugly, she tried some "harder" face angle and it's a nightmare...
What is worst is that the 3/4 side face angle is one of the most basic angles of all. It's one of the earliest things manga students are taught about - it is part of the basic skills needed to draw manga.
The clothes are a mess in her art - the cloth of the dresses look like made out of paper or burnt material, there's no weight, feel or sense of realism out of them (creases, folds etc.)
Over here is an excellent example of a mangaka who has mastered the very style he has created and is able to freely play around with his craft.
https://flic.kr/p/2oBXHkZ
Takeuchi is not like Hirohiko Araki who had a genuine love and interest in fashion and modelling. Sure, there are cases where he copied photoshoots and applied them to his work BUT he implemented this feature from his very early beginnings in most of his works.
Today, the 'Jojo poses' have become part of the very DNA of Jojo's Bizarre Adventure and by extension part of Araki's DNA itself.
https://flic.kr/p/2oBSpgb
Takeuchi is not like Masami Kurumada either, who has a very particular style and reuses a lot of the same poses in his story board (especially since he hit 60). Masami Kurumada has had a career spanning over 50 years now with 4 major manga hits. Over the years, he has cemented his very own style and touch, for him today to not need to experiment anymore.
The same cannot be said for Takeuchi who has only done 1 series for 5 years in her whole life...
You cannot say her 'awkward anatomy' and
lack of knowledge in composition is part of her style because she HASN'T experimented enough...
Tite Kubo is another mangaka who has popularized the use of fashion in manga. He has made tons and tons of color spreads of the characters posing with fashionable clothes from the very early beginning and you can see his love for fashion throughout his growth as a mangaka.
The same, again, cannot be said for Takeuchi who only copies photo shoots.
https://flic.kr/p/2oBXku6
https://flic.kr/p/2oBWarM
https://flic.kr/p/2oBXHoQ