What does the Mini-shipping bin do that the regular one doesn't?

[Slim]

As stated

[esturias]

It's pretty obvious - you can place it wherever you want. Even indoors.

[NBOX21]

You can store up to 9 items in the mini-shipping bin, but you can take them out whenever you want before the end of the day just in case you may need it for something as opposed to only being able to take out the last item deposited in there before day's end.

It can also be used as an inventory item, allowing you to pick it up and place it elsewhere wherever you want without the need to ask Robin to place or move one for you.

[Nakos]

Yep, the ability to place it where you want is one of the biggest positives in my opinion. I like to put one inside the Greenhouse for example.

My keg sheds and barns are another prime location.