This step was a little confusing to me going through the process.  I'm not sure there is a use case where you actually want to run this on some non-inspector web page?  Maybe I'm misunderstanding something here - but if opened *not* on devtools, I'd almost pop up an alert that says - "You should run this snippet after undocking devtools and opening inspector on itself", rather than giving them an option to proceed.  I may be misunderstanding though.