Space quota for Time Machine

I noticed that Time Machine backup can not be accessed through Finder, and there is a separate network device “MyBookLive-backup” showing on the network device list.  However, it can not be mounted or modified on the desktop.  Is that normal? 

If this “backup” space can not be accessed, there is no easy way to impose the TM size limit, such as those being suggested on Apple Support sites using a modified sparesbundle files.  Will future program update through WD be able to allow size limit?