Currently, when creating a bundle, there is no way to see both the preview and the full brush name, because the window is not resizeable.
This makes the window extremely hard to work with. Please allow me to resize this portion of the window so I can actually read the text and see the thumbnail.
Yep, this bothers me too, when it comes to compile a larger bundle.
I changed your title to not be misleading; Resource manager is the dialog you get in Settings → Manage Resources. Additionally there is also Resource Libraries Manager (“Bundle manager”) in Settings → Manage Resource Libraries.
That dialog, btw, truly needs some UI changes but frankly, much bigger than this I hope to at some point add the left side of the Resource Manager here to be able to easily find resources.