500ml to 440ml?

Edit: the 440 on the right, is the last of a can that I bought in a four pack. The 500 on the left, is one of three I bought as singles.

Packaged Guinness comes in 440 milliliters. Single cans of Guinness come in 500 mL.

Apparently, that's how Guinness does it here in Canada.

And apparently, I lazily avoided any attempt to research or apply any level of critical thinking before posting.