Speaking of Eliminating Waste

This morning I was making my kid's sack lunches and I ran out of Ziploc bags. So, I sent one of the littles downstairs to grab another box. I laid one of the old bags on top of the new (I have no idea why...) and this is what I saw.

What is going on here?

Did I buy a different brand/size of bags?

Did they change the sizes and not tell me?

Nope.

The sizes are listed as the same 6 1/2 in. x 5 7/8 in.

So I whipped out my trusty ruler.

The larger bag is 7 in. x 7 in. while the smaller is 6 3/4 in. x 6 5/8 in.

What is going on here?

A freak of manufacturing or are they eliminating wasted space by shrinking the sizes?

I don't know what to think.