it's cosmetic. if you want to compare it's like shiny pokemon.
looks good on the 1st profile player tab (congrats you have tall player!) but it didnt affect your squad, still based on % and white skills.
but i think the preferred foot does have impact in-game since 3d.
i usually switch my winger/fullback/whatever that pairs left & right if they didnt perform in early minutes in game and somehow it has impact.
or it really isnt and just cosmetic. i dunno
in 3d everyone have the same height, they only differ on skin colors and hairstyles..i'm not sure bout facial hair. didnt zoom enough & my phone is small. need enlightenment from others bout this