Now add cold boiled water. You can pour more or less water. Water simply regulates the density of mayonnaise. And yet, with water, you can add, for example, the missing salt.
Here's mayonnaise for you, I tried it, and no, you don't have enough salt there, but the tastes are different. Add a little salt to the water and pour into the mayonnaise, not forgetting to whisk. Tried. What, again, is there not enough salt? Not anymore. However, if there is still some salted water left in it, add it.