When you say you're doing an incremental backup, do you mean that your backup job (General - Backup Method) is set to incremental, or that the SQL part of the backup (Microsoft SQL - Backup Method) is set to Log?
If it's the latter then no you wouldn't see any data since you've only backed up the transaction log data, not any of the actual database content.
But if it's the former then yes you should see something in the database size. Just done a test backup using an incremental on the server, and full on the SQL database and afterwards I do indeed see a list of database sizes in the restore selections list. Have you checked the backup log and found the section which deals with the database backup, and confirmed that it is reporting the databases being backed up, that there is an amount of sql data being backed up, and the 32MB isn't just coming from something else on the server outside the SQL databases?