@strangerquefuir
OOF!!! Now theres a twist!! If it was MC's bday and she was the one who should've been the focus and center of attention in the first place. But coddled lil sis fake faints as she sees MC walk in. I can totally see that happening.
Plus MC was specifically trying to express her gratitude for being born. Would make sense if it was actually HER birthday. And she was just trying to be humble and give out her thanks. BUT the sister is holding a present.... but I could also see the parents buying the sister a gift on MC's bday.... DAMN. But its still awkward because the sister already started hyperventilating, and fainted by the time MC walked over and was trying to be polite.
I haven't read the novel, but this scenario would help MC keep the image as selfless and pitiable. The kind of person who (was forced to) put others before themselves, and NOT someone who is desperately trying to steal some of the shine. This way, it'd be lil sis who is always stealing MC's shine (which the following pages did a good job of hinting towards).
It must have been an important scene in the novel for them to want to include it into the promo, but even a LITTLE more context would prob make a world of difference. Because the way it unfolded here in the promo is looking pretty questionable.