Love vs Liberalism
The whole debate of why someone would instruct their sister to dress appropriately and not somebody they see on the street, is a typical case of Love vs Liberalism.
Love When you love someone, you want the best for them and thats what love really is, you do things when others don't even want them done.
*For example, your mum would be happy to have a gay friend, but would she like having a gay son? Thats a good example of Love vs Liberalism. *
Bottomline, your mum is happy to be a part of liberal society but she loves you and wants the best for you from her own perspective.
Liberalism On the other hand, Liberalism, is part of our society that pushes for individualism inside every person. You don't love a person walking down the street enough to ask them to change something.
For example, I saw someone on street playing extraordinary yukalaylee jingles and I offered him to record his music for free and then he can send it out to music companies but he refused. I can't force him to do it even though it is in his best interest.
*Similarly, I would instruct someone I love how to dress but not someone I see on the street. This is far from hypocrisy. *
nicely put Navid