>Claude sometimes thinks in a conceptual space that is shared between languages, suggesting it has a kind of universal “language of thought.” We show this by translating simple sentences into multiple languages and tracing the overlap in how Claude processes them.
I think concept here means it is assigned a point or an area in the many-dimensional embedding space. The "concept" has no obvious form, but similar words, synonyms or words from another languages meaning roughly the same are very close together in this space.
> At some point in this process it naturally abstracts concepts from languages: "as a child"
Is true. I don't know of any way for the model to represent concepts.