why the 2nd element of the yield in data_generator is of size equal to batch_size?

[sonalrpatel]

Following is the link to the exact line of code. I just want to understand the theory behind it. https://github.com/qqwweee/keras-yolo3/blob/e6598d13c703029b2686bc2eb8d5c09badf42992/train.py#L182

[sonalrpatel]

Also refer to following link for another similar question. https://github.com/qqwweee/keras-yolo3/issues/761#issue-1004543362