She's only 16 but the outfit they give her are usually too mature and quite revealing compared to her other minors peers from other groups. Remember in Fearless mv they have that weird pumping floor movement that probably supposed to be part of their choreography and obviously not suitable for minors.
Le sserafim concept are mature and quite sexy while Eunchae is still a minor. She suits it, but it didn't erase the fact that she's only a kid.
Maybe because Le sserafim consists more older members so no one really care that much about Eunchae position as an underage member in this group. I think she is a perfect fit in Lsf, just her age sometimes make me wonder, is it okay for her to be in this group?