Thanks, @Rath_.  That explains things perfectly.  I appreciate it.

I'm a new Trezor user, raising this old thread because I have a similar question.

What happens if I link to Dropbox for labeling accounts and transactions, but then lose access to Dropbox?  Will the accounts/transactions revert to default names, or will I encounter problems reading my accounts?  The instructions say that you can back up the Dropbox file.  Does that mean you can point to a file anywhere on your computer or on a cloud service to use the labels?  Thanks in advance for the help.

Many thanks for the replies.  Much appreciated!

When I first set up Electrum, I did not use two factor authentication.  I would like to add that now, but understand I cannot do so with my existing installation.  If I reinstall Electrum using my seed words, will I have an option to add two factor authentication?  Thanks.