It puts you in a pager (most probably less if you installed MSysGit or Github for Windows), because the output you requested is longer than one screen page.
You can scroll up/down/left/right with your arrow keys, the Page Up/Page Down keys and the J/K/H/L keys.
To show inline help, press ? and to quit, press Q.
You can use a different pager or turn it off if you want to. As man git config points out, you can use the core.pager setting to set it to a different pager, or set its value to cat to disable pagination for all Git commands.