Notice, they are labeled. Labeling is important, especially if you work with more than one herb at a time, blends, or letting them brew for longer time periods. Besides the names of the ingredients, I like to add the date I started the extracts. Once they are poured off, I will enter the start date and press date along with the name of the herb and source of materials into my herbal log book.
There isn't any particular significance to the herbs pictured. They are some I am interested in, and some that I thought would be useful, some that a friend needed, and some that I wanted to experiment with.
I'm really looking forward to pouring these off, as I like to compare tastes, aromas, and color nuances between herbs when it's time to bottle. Making the comparisons and having the contrasts helps me get a better feel for identifying each herb. If I have identical herbs from a previous batch on hand, (say, from remaking when I began to run low, or a store bought preparation) I will also compare apples to apples.