The brevity of Dart’s letter in no way reflects the enthusiasm it contains. His doctor has just told him that a) he doesn’t need another operation – at least right now, and b) he’s going to write a letter recommending Dart for a 10-day leave as soon as he’s strong enough to leave the hospital!
He voices a wish that Dot would teach him how to write such an interesting letter in so few words, deeming her letters “models of perfection.”
Dart admires the snowy landscape out his window before signing off with all his love.