Keith Casey moderated a live code review. The event was lightly attended due to a certain holiday, but multiple code reviews were still made, and coding principles discussed.
Four types of things to look for:
Logical/Fundamental issues - Obviously this includes syntax errors - there were none - but also things related to the proper flow and functionality of the class.
Security/Performance issues - Just because code works as designed doesn't mean it doesn't do other things you don't want it to. Or to put it more coherently: the code should accomplish the desired task and no more while using the required resources efficiently.
Best Practices/Standards - This is somewhat of a squishy subject. There are numerous competing coding standards out there and they're competing for valid reasons. Luckily, Best Practices are relatively clear and becoming more established.
Style/Preference Choices - This is the squishiest point of all. This starts to touch on the design of the code versus the rest of the system, whether the code should support multiple [choose one: operating systems, databases, http functionality] which really only matters if the code is supposed to be re-distributable.