Originally there were 2 people working on the webtoon (seen on title pages of ch 1-10) then only 1 person after that.
Whether or not it's the same artist (Lee Oh vs. io), I will surmise that some cuts were made to accommodate the artist. Which ultimately means that her mouth details ended up on the chopping block.
You are now looking at Ms Potato Head with the "Oh" mouth.
Him: He will use his kid to spend more time with you
Her: No, you're overthinking it. Why're you being childish. (gas lighting)
Him: He's interested in you.
Her: No he's not, I said he's not before. (How would you know about a stranger's intent towards you without discussion?)
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Her: I want us to reach a better understanding.
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Well maybe you can reach understanding if you said your feelings about Mr Cousin, ie. "I'm not interested in him, only in you".
But no, she said the most used lines when confronted about an attraction to a male friend, which usually ends up being true.
Mr Red Prince seemed fine and dandy with being future engaged to princess since the one he wants to mess with is just a maid and can get to her whenever.
But since that maid is now here and not dressed like a maid, he must get her before being engaged.
In other words, consorting with the help is acceptable as long as you're royalty, unless you're consorting with a high status holder, then you will be ruined.
Go Duke, ruin his face!
I mean let's be honest he just wanted to beat the duke in the original time line.