I'm not really sure what do you mean. Is look the look(1), "display lines beginning with a given string" one ?
Within the CPAN shell "look" will extract the archive and give you a shell prompt. For example:
cpan> look Test::Exception
Running look for module Test::Exception
Trying to open a subshell in the build directory...
Working directory is /Users/adrianh/.cpan/build/Test-Exception-0.25
(1/501) ~/.cpan/build/Test-Exception-0.25 mitchum% ls
Build.PL Changes MANIFEST META.yml Makefi
+le.PL README lib t