Claiming to be 30, when you're 40 is LYING about your age.
Claiming to be 21, when you're under age is LYING about your age.
Saying you're 91 when you're obviously around 30, or 40, is not lying about your age, it's being facitious; or, at worst sarcastic.
In my opinion, the fact that the statement is so unbelievable (When her picture was showing,) keeps it from being a lie; since nobody with normal intelligence and the ability to see, could HONESTLY claim be decieved by it.
It takes on more of a tounge in cheek, "I'll tell you later" tone.
Without the picture showing, I think the tone is saying...
"If you only want an age brackett, and can't look for something timeless and beautiful in my heart, I might as well be 91 as far as you're concerned; don't bother me."