Callie 6 is a Genesis 2 shape, and Bree is a Genesis 2 texture.  If there are Poser Companion files, which there are in this case, the DSON Importer handles the UV changes within a character family if you own the base character.   Thus, I can apply V6 textures to Josie 6 without issue.  However, I wouldn't be able to apply Callie 6 textures and have them work properly because I don't own her.

You do need Studio if you are trying to put a Genesis 1 texture with V5 UVs on Genesis 2.  (or a V4 texture if the V4 UVs happen to be installed.)  Now that I think about it, Bree is also the default texture for V5, albeit with Genesis1 material zones(same UV, tho'),  so perhaps that material got applied, although it is in a different folder.

Crosspost; yes, they may be distortions when applying a V6 texture to C6 but there shouldn’t be any gaps...

----------------------------------------------------------------------------------------

The Wisdom of bagginsbill:

"Oh - the manual says that? I have never read the manual - this must be why."
“I could buy better software, but then I'd have to be an artist and what's the point of that?"
"The [R'osity Forum Search] 'Default' label should actually say 'Don't Find What I'm Looking For'".
bagginsbill's Free Stuff... https://web.archive.org/web/20201010171535/https://sites.google.com/site/bagginsbill/Home