Can anyone tell me what that is

I am a new Boxer Mom

Brindee is 11wks old. We're having the same problems that all puppies go through. Potty training

I know she'll get the hang of it soon. I've read alot of good advice today
I'm just wondering what kidney-beaning is.
Thanks, Hope everyone has a good day
How do I put a picture of Brindee with my info.
Thanks