While I would normally like the idea of reusing existing components, I'm not sure it's appropriate here. Code Review is different from Stack Overflow and our questions are constructed differently.
How are Stack Overflow and Code Review different?
Stack Overflow, like most Stack Exchange sites, favors questions with general application. So it wants small sections of code with no details specific to the user's exact problem. Stub and hypothetical code are allowed, even encouraged, if they demonstrate the problem.
Code Review is different. We take code that solves very specific problems and many of our questions and answers are only relevant to that one person. For everyone else, it's just an example of how to write code. We encourage people to post their entire programs in runnable form, and we prohibit stub and hypothetical code.
A good question for Super User could be posted on Stack Overflow with the only problem being that it was off-topic. If a question that fits Code Review were posted on Stack Overflow, it would have multiple problems. For example, there would be too much code, so it would be reasonable to ask for a minimal example.
Link to a new page
If the link goes directly to our generic about page (the tour), it won't be making specific advice for Stack Overflow users. The tour is intended for use by people coming from outside the Stack Exchange network as well as people from other sites. It doesn't know that the person is coming from having just posted a question on Stack Overflow. So it will be giving much less specific advice. We could do better. We could send people to a page specific for questions coming from Stack Overflow that emphasizes the differences between the two (possible a question on meta). That page can link to the tour and the help pages.
Does someone coming from Stack Overflow need to know about reputation, editing, and commenting? Not so much. Does that person need to know that we require real, working code? Absolutely. But we don't mention that in the tour. We do explain that this is a question/answer site, which most people already know by that point (when coming from Stack Overflow). The tour has to meet the needs of people who've never heard of Stack Exchange. It's not the best starting place for someone from another site.
The help pages would be better. They at least do contain information about posting the code. Of course, there are so many of them that people may miss that.
An alternative might be to change the tour page to better emphasize the differences with other Stack Exchange sites. I'm not sure how to fit that into the existing template though. The tour is more designed to remind people of the similarities with other sites, as the basic template is used widely across Stack Exchange.
A new page might also be easier to edit. As far as I know, only moderators can edit the tour. A quicker, more accessible edit cycle could allow the page to evolve faster. The process for a non-moderator to edit the tour page is cumbersome enough that someone has to be really motivated to pursue it. Minor tweaks just aren't worth it.
General changes to the tour
The section on tags could emphasize that on Code Review, every question should be tagged with the language in which the code is written.
The second section could remind people that our site reviews code, so you have to post the real, working code, preferably in complete, runnable form. Leaving out some or all of the code is a common first post mistake.
But like I said, I don't think that minor tweaks are enough for this purpose. I think that we could emphasize just a few differences with Stack Overflow and get major improvements in the quality of redirected questions. Maybe we should make these changes, but even with them, I don't think that the tour is the best page to land people coming from Stack Overflow.