Lesson 03 Data Sources & Transformations

The text says:

It is important to note that when doing using these objects, the transformations occur in the browser, not in Python.

But it does not say why is that important to know. What difference does that make to me as the coder?
Thx.

An immediate corollary of the computations happening in JavaScript rather than Python is that the results (e.g. the details of a colormapping) are not available to your Python code.

Oooohhhh. Ok. Is that an issue? Do people code some sort of workaround or are they just happy with the Python code, since they can always just re-execute it as needed?