I'm not about to install that extension and find out myself as that could cause some... serious problems... but that was my first thought as well. What's to stop this from doing something nefarious? Its sandboxing privileges are not remotely clear from what's in the app store, and I don't see of any reasonable way to contain what it can and cannot do.

Granted this is equally a problem with any terminal emulator that you didn't compile yourself after examining the source code, but I have quite a bit more faith in Apple and the various Linux repo maintainers than some random guy publishing to the chrome app store. I don't know if Google even claims to vet its contents, but if they do I know they do a terrible job because I've ripped open some extensions to confirm they're doing some sketchy stuff (nothing insecure or worrying, more like adding affiliate links to your entire browsing experience)