You stuff herbs into the mill and creak-creak-creak grind the herbs onto soup, salad, pasta, or whatever. It's kind of fun, and it's a hands-off way of chopping herbs.
If you're chopping a lot of herbs for a recipe, this probably isn't the best way to do it, but for a small amount of herbs (particularly for garnishing) it works well.
But where this really shines is for use at the table, where people are adding herbs to their own dishes, whether it's basil and oregano for pasta or pizza, or parsley and mint for a salad or cilantro for tacos. It's easier and less messy than passing around a bowl filled with chopped herbs.
Please note that the body style of the herb mills for sale online now (the bottom photo) is different from the one I have (the top photo).
I think the new one is definitely more attractive, but the chopping blades seem the same on both models, so the one you buy should work the same way as the one I tested.
Who's it for: People who use chopped herbs.
Pros: Works well. Great for serving herbs at the table.
Cons: Probably not what you want for large quantities of herbs.
Wishes: For people who want to offer choices, it might be fun to have different colored mills, so they could tell people that blue is basil, orange is oregano, or whatever.
Source: I received this from the manufacturer for the purpose of a review.