The analysis of a text #1

The narrator recalls his adolescence.
He was an apprentice for Mr. Spenlow.
He and Mr. Spenlow's only daughter Dora fell in love with each other, but after Mr. Spenlow's sudden death, she moved in with her two aunts.
Now he is going to be married to Dora.
Traddles is his best friend and Sophy is his fiance.

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Sophy arrives at the house of Dora's aunts, in due course. She has the most agreeable of faces, - not absolutely beautiful, but extraordinarily pleasant, - and is one of the most genial, unaffected, frank, engaging creatures I have ever seen. Traddles presents her to us with great pride; and rubs his hands for ten minutes by the clock, with every individual hair upon his head standing on tiptoe, when I congratulate him in a corner on his choice.
[David Copperfield by Charles Dickens]
I'd like to know what "every individual hair upon his head standing on tiptoe" means.
Thank you in advance for your help.