Starting a new game+ lets you keep all your pictos from before which is nice cause you can grab them again in the same spots. Things get more interesting with duplicates since you can combine them to make them stronger though nobody's quite sure about all the details yet. The tougher bosses in ng+ might drop better versions of pictos, but there's no official guide about exclusive ones. Getting the most out of your pictos probably means doing multiple runs, but don't worry too much since your first-run pictos will still work fine. Good to know that while enemy difficulty ramps up, having doubled-up pictos from collecting them again can help even things out.

Pretty much any picto spot you remember from your first run will be there again, and getting extras isn't a bad idea since you can work with duplicate drops. Just keep in mind the fights will be tougher this time around, especially those upgraded boss versions that show up.