Kinda wish we got an explanation of what 2.5D anime means, but I guess if Japan uses "3D" for irl stuff, then 2.5D probably means anime made with CG animation.
One of the PR's here. The literal translation was just "2.5D production responsible." We weren't really sure what to make of it either lol
The idea was nice, even it's unlikely that voice-san would choose two girls who are more or less yuri for each other already. And they were even yuri fans, so it wasn't that shocking for them.
The dilemma would be way bigger if one or both were closet lesbians or even straight.