めでたい
めでたい · medetai · JLPT N2 · i-adj
happy
🎍 Classical 愛でたし: worthy to be admired and cherished (from 愛でる, to admire)
おめでとう (congratulations) comes from this adjective, so it carries the sense of a joyful, auspicious occasion. The New Year pine decoration emoji fits that celebratory feeling.