This is an intermediate knitting technique that lets you add nuanced shapes to your knittings, particularly bulges and bends! I use this technique in my tiny walrus and tiny alpaca patterns, for example.
I thought about making a custom tutorial for the wrap + turn technique, but this is really just a general knitting technique that many people have covered already.
For a photo tutorial, try this one from Purl Soho (a boutique in NYC where you can find tiny mochi kits!).
For a video tutorial, check out this one from VeryPink Knits.
One note: I don’t tend to pick up my wraps on subsequent rounds of knitting—I just don’t usually mind the small gaps that this technique leaves. But there’s nothing wrong with picking them up either, if you prefer the way that looks!