Is this a "correct application" after a hyaluronic acid injection on nasolabial folds?

Hyaluronic acid fillers can be molded and "massaged" into the desired shape after injection.  This is typically done right after the injection, but can be done up to a few weeks after.  

We do not recommend that a patient massage after one of our filler treatments but other doctors may. In my practice every cosmetic patient is addressed separately as there are no "cookbook" approaches even after almost 20 years of Botox and filler experience.We use many different approaches with Botox and various types of fillers in the same patient to achieve a optimal correction. I would recommend you discuss your issue with a dermatologist board certified and experienced in Botox and fillers in your area.

I generally massage right after injecting if an area looks uneven, but sometimes it is just swelling. Therefore, I don't recommend massage by patients until at least several days have gone by so that they don't ruin their result by overly aggressive massage.  I advise patients if they feel a lumpy area, but don't see it then they should leave it alone as some areas need more dermal filler placement than others which can feel different to touch.

Many practitioners will massage immediately after hyaluronic acid injections to check for lumps.  I would say doing it 24 hours later is not necessarily wrong, just a different style.  Medicine is both art and science.