Did you know that before Estonia had the kroon, it had the mark? It's true. Up until 1928, things were in marka, not krooni. I came upon this interesting site that has images of money from different countries during different periods.
My guess is that from 1918 to 1928, business was done in marka and penni. Here is an example of a 5 penni note:
You can also glimpse some more scenes of daily Estonian life from the newly founded 'peasant nation.' These appear to be fishermen:
Here are some interesting images from the currency when it switched to krooni, which I guess depict Estonian national values in the 1930s. There are some like this farmer:
And then there is this woman, who has appears to be holding some kind of harvested vegetable or grain in her hands:
Then finally this industrious gentleman, perhaps representing Estonia's fondness for workoholic behavior: