X100T Multiple Exposures Mode and Owner's manual

[Bella]

I bought a X100T last year, and am totally new to the modes Fuji provides. 

I'd like to use the Multiple exposure mode, but it's not clear from the manual whether the final image blend is the result of exposures using additive, average, bright or dark options, as provided in later models, or something else.  https://fujifilm-dsc.com/en/manual/x100t/shooting/multi-exp/index.html
Grateful for your assistance to know which exposure option X100T uses?