apple pencil 2 gen made in vietnam vs china

Apple does have manufacturing facilities in multiple countries, including China & Vietnam.

Again, if both of these were purchased directly from Apple or an Apple Authorized Reseller, they should be original products. However, and regardless of the boxes they come in, they should be physically identical if both being the exact same model.

Did you purchase both of these Apple Pencils directly from Apple or an Apple Authorized Reseller? If so, then they should be the original products. If not, then they could be fakes.

There is no way, just by looking at pictures, that anyone here can confirm their authenticity.

The serial number of the one made in Vietnam is known by Apple, but not the one made in China.

Yes, the boxes shouldn't matter. However, if they are physically different, then one of them could be a fake. You said you got one from an authorized reseller, but how about the other one?

Regardless, if you are concerned, then visit your local Apple Store to have them verify them to be original or not.