Guys are instinctively and biologically drawn to girly girls.
The girly girl has several feminine markers that make her instantly stick out in a crowd.
She is wearing makeup that enhances her face and beautifies it, as well as feminine clothes that accentuate or show off her feminine figure.
Since guys are stimulated by what they instantly see on the surface, they are quickly drawn to a girly girl who is showing off her femininity.
To this extent, he notices a girly girl first.
He is used to feminine women.
That is what he grew up around.
His mother and sisters are feminine.
He grew up around female family members who exhibited traditional feminine behavior.
There were more than enough occasions where he was frustrated in having to wait on a female sibling to get out of the bathroom as she went about taking several hours to have a bath and do her hair and makeup.
Not to mention the number of times she would come into his room wearing a traditionally feminine outfit or dress that she was thinking about wearing to a date with a guy and asking for his opinion on what he thought of it.
All behavior that didn’t take long for him to realize was usually exhibited by feminine women.
He knows what “feminine” is because that is what he grew up around.
When he sees a girly girl, he instantly attributes her physical appearance as that of a feminine woman.
The first girl he ever had a crush on in school was a feminine girl.
The first thing he noticed about her was her long flowing hair and sweet flowery scent.
All he really knows in regards to what draws him to the opposite sex are appearances and behaviors that are usually attributed to a feminine woman.
To this extent, if there is a tomboy he sees at a social event, he doesn’t instantly notice her.
He notices the girly girl standing next to her because she has the physical appearance and demonstrates feminine behavior that he is familiar with and grew up around.
To this end, the girly girl is the one who grabs his instant attention.
She is the one he approaches, as long as he deems her to be physically attractive.
The tomboy standing next to her is either not noticed or assumes that she is not heterosexual.
In this day and age, a biological girl whose behavior and appearance come off as masculine is often regarded as someone who isn’t heterosexual.
When you have a bunch of visible tattoos, as well as wearing baggy or androgynous clothing that hides your feminine figure and little to no makeup as a tomboy, standing next to a woman who is dressed in a traditional dress that complements her feminine figure and makeup that accentuates her facial features, you are practically invisible to guys.
Therefore, yes, guys prefer girly girls.
In relationships, there is usually someone who embodies the masculine role and someone who embodies the feminine role.
This goes for both heterosexual and homosexual relationships.
A yin and a yang, so to speak.
Since he is a man, the moment he sees the girly girl standing next to you, his brain and biology instinctively see her as someone who would fit the feminine role, given her feminine physical appearance, presentation, and behavior.