It's just a summary generated by a really tiny model. I guess it also an ad-hoc way to obfuscate it, yes. In particular they're hiding prompt injections they're dynamically adding sometimes. Actual CoT is hidden and entirely different from that summary. It's not very useful for you as a user, though (neither is the summary).
They hide the CoT because they don't want competitors to train on it
The early version of Gemini 2.5 did initially show the actual CoT in AI Studio, and it was pretty interesting in some cases.
Agree the raw thought-stream is not useful.
It's likely filled with "Aha!" and "But wait!" statements.