Using an instance variable in initialize before defining it

I am a Ruby beginner. I am confused by an example from Why's Poignant Guide.

I understand the following example's use (also from the Poignant Guide) of picks in initialize, because it is passed in as an argument.

class LotteryTicket

  NUMERIC_RANGE = 1..25

  attr_reader :picks, :purchased

  def initialize( *picks )
    if picks.length != 3
      raise ArgumentError, "three numbers must be picked"
    elsif picks.uniq.length != 3
      raise ArgumentError, "the three picks must be different numbers"
    elsif picks.detect { |p| not NUMERIC_RANGE === p }
      raise ArgumentError, "the three picks must be numbers between 1 and 25"
    end
    @picks = picks
    @purchased = Time.now
  end

end

But how does initialize in the following example start using picks without picks being passed in as an argument? Here, note1, note2, note3 is passed in instead. How does that ever get assigned to picks?

class AnimalLottoTicket

      # A list of valid notes.
      NOTES = [:Ab, :A, :Bb, :B, :C, :Db, :D, :Eb, :E, :F, :Gb, :G]

      # Stores the three picked notes and a purchase date.
      attr_reader :picks, :purchased

      # Creates a new ticket from three chosen notes.  The three notes
      # must be unique notes.
      def initialize( note1, note2, note3 )
        if [note1, note2, note3].uniq!
          raise ArgumentError, "the three picks must be different notes"
        elsif picks.detect { |p| not NOTES.include? p }
          raise ArgumentError, "the three picks must be notes in the chromatic scale."
        end
        @picks = picks
        @purchased = Time.now
      end
end