It's modal, so it blocks the entire browser until the dialog is dismissed. That's terrible interaction design, except for actions that would melt your computer.

I understand that the library focus is on visualization and not on realistic and usable examples; I put the blame on browser implementors - they should have fixed that problem years ago, instead of relying on developers to do the right thing.

Edit - Update: I've tried it on Firefox and it does the right thing, blocking only the current tab; blocking the whole application must be a Chrome-only thing.