The reason is that Glimpse has to be enabled first. For this I opened the page Glimpse.axd in the root of my web application:
NOTE: Glimpse stores the info if it is enabled or not in a cookie called glimpsePolicy. That means, when you later access the page again, Glimpse will be enabled already (or not).When you look at the Glimpse tabs, some like Request, Server or Trace appear familiar from ASP.NET Tracing. But there are also some other tabs. Just play around with them a little bit.
Entity Framework PluginAs useful as Glimpse is so far - that is not all. You can easily add additional tabs to Glimpse. A complete list of all available packages can be found on the Glimpse Extensions page.
The Internet Application template I used above contains some database access in combination with the user stuff (Log in, Register). Therefore I added now the Entity Framework Plugin.
I just had to download the NuGet package Glimpse.EF5. After compiling I refreshed the home page and found a new SQL tab in the Glimpse window. Only the tab was disabled since no database access was done for the home page.
Then I logged in, but again the SQL tab was disabled. This happened because there several requests executed for the log in, and only the last request didn't access the database. For problems like this Glimpse provides the History tab: