VASTRA: But he is The Doctor. He has walked this universe for centuries untold, he has seen stars fall to dust. You might as well flirt with a mountain range!
CLARA: I did not flirt with him.
VASTRA: He flirted with you.
VASTRA: He looked young! Who do you think that was for?
CLARA: … me?
VASTRA: Everyone. I wear a veil as he wore a face, for the same reason.
CLARA: What reason?
VASTRA: The oldest reason there is for anything: To be accepted.
"Many have interpreted the scene as something of a ‘take-down’ aimed at fans perceived only to be into the show for an attractive young lead (a ‘judgement on the quality of their hearts’, as Vastra says - a ridiculous notion in and of itself, but that’s for another day), but if anything it’s about Doctor Who itself. Vastra notes that The Doctor wasn’t just appearing young for his companions, it was for everyone - even the audience itself. The character and the show wanted to be accepted, either in-fiction by his traveling associates but also in the real world, by a new generation of viewers. He had to hide his age, his quirks and his weirdness, as did the series - until now, where he can cast off his facade and show who he really is to both Clara and the audience.
But it’s in Clara’s, and therefore in this analogy, the audience’s furious retort, that its made clear:”
I am not sure who you think you are talking to right now, Madame Vastra, but I have never had the slightest interest in pretty young men - and for the record, if there was anybody who could flirt with a mountain range, she’s probably standing in front of you right now!
Just because my pretty face has turned your head, do not assume that I am so easily distracted.
"If Vastra’s speech is a supposed ‘screw you’ to people unwilling to accept an older, weirder Doctor for who he is, Clara and the audience are replying with ‘Well screw you for thinking we’d act like that’. It symbolises both the shows willingness to get a bit more bizarre, and the audience’s willingness to accept and enjoy that. I think we all had a bit of Jenny in us after Clara got that one out, and engaged in some damn fine clapping."
From “We are entering an era of acceptance for ‘weird’ pop culture” by James Whitbrook