As a non-native-english speaker foreign to ML and CV, what does that mean?

In case you're asking about the parent comment (s/Differential/Differentiable), it means the title should be "differentiable CV" (instead of "differential CV").

"Differentiable" describes some computation for which derivatives can be computed. "Differential" is a more general term which means that something has to do with differences, e.g. differential equations deal with equations that specify how things change together.

With the recent surge in deep learning came significant improvements in optimization techniques and hardware, making it feasible to formulate some computations in a differentiable manner. Doing that allows one to optimize the computation process relatively efficiently, at least in theory. Some other examples: differentiable programming[0] (other differentiable techniques are a subset of this), differentiable rendering[1], differentiable signal processing[2].

[0] https://en.wikipedia.org/wiki/Differentiable_programming

[1] https://arxiv.org/abs/2006.12057

[2] https://github.com/magenta/ddsp

This library is super cool because it implements a ton of important classical computer vision methods in a way that is compatible with automatic differentiation. So you can combine modern deep learning methods with classical methods