class User
	include Mongoid::Document
	embeds_many :profiles
end

class Profile
	include Mongoid::Document
	embedded_in :user
	field :likes, :type => Array
end

User.last.profiles.create(:likes => ["red","orange"])
User.last.profiles.where(:likes => ["red","orange"]).count
 => 0

class Profile
	include Mongoid::Document
	field :likes, :type => Array
end
Profile.create(:likes => ["red","orange"])
Profile.where(:likes => ["red","orange"]).count
 => 1