I know what you mean. I cannot imagine it at all. That was one of the ways Muffin "talked" to me and told me what she wanted. If I was in another room and she wanted to play, she'd stand by her toys and bark until I came to play with her.
I thought it was sooooo cute! Now, Kacee has only "spoken" very little, but when she has done it, it was her speaking to me. She wasn't barking at anything she saw.