Does Code Review Involve Testing?

When you review a pull/merge request from someone, do you check out the branch and run the build? I usually dont, but some people do. Their obvious reason is: running a build, or even testing the product manually, helps find more important errors. Just looking at the source code may not reveal all visual defects recently introduced to the HTML/CSS, for example. Its better to check out the branch, start Apache, open the site in Chrome, and see whats broken. Then, make a screenshot, attach it...