it's all about how facial features relate to eachother and how they proportion against eachother and how they match up with our ideas of a face that is typically "feminine" (or, the natural face of someone 'assigned female at birth' to be PC)

so that's firstly a very eye-centric face where the eyes are larger to make other proportions look smaller and also drawing most attention to the top third of the face and having that be the widest part of the face (rather than a"masculine" face which is considered to be very square, hence 'manly' queens being called "bricks" i guess?) so like prominent cheeks too (but not necessarily strong cheekBONES, ill get to that in a sec) - a smaller forehead and/or lower hairline, a smaller nose can help with the features all looking nice and petite but big lips are good because bigger lips are firstly considered more feminine and eye catching especially with makeup on but also can balance out a strong chin and/or jaw SINCE a smaller chin and jaw can help with the feminine 'illusion'

one thing i've found for looking especially "fishy" is not contouring as much in the places where it's not needed, like the Drag Queen Cheek Contour which sometimes can be used to sculpt out a new cheek that really works for the face (take Raven or Trixie for example who draws out these great big rounded cheeks therein adding roundness to the face and a cheek that certainly doesn't look 'masculine', or Pearl who draws her cheeks quite low, which gives her more cheek space and takes up jaw space so the jaw looks more petite) but oftentimes a shadowey, strong bone structure (especially on the likes of the temples) can be very aging and masculine looking, so it's all about finding a balance of drawing these new features on but also keeping it so you look soft (i've found for me, being quite boney anyway, that a minimal cheek contour looks cleaner and more feminine)

i also explain this and visually demonstrate in a tutorial where i try to look as fishy as possible HERE^plug

SO, a queen who has any of these features before makeup is probably going to end up looking fisher