It's the matte unglazed mosaics that suck up dirt; they have a fine grin surface that holds on to the dirt. The glazed type whether matte or glossy is a smooth surface. Is this a DYI project? Be sure the mosaics are from the same source to ensure size consistency.

If they're going to be on a floor then you want matte so they're not slippery.

Both fair points. How big is the floor? Some bathrooms are so small it's not an issue, slipping but looking grungy always a bad look particularly in a bathroom.

Whatever you decide to do will advise that your tile needs some "grip" as a wet bathroom floor can be a real danger especially for older people.

The bathroom is 8 x 10. Thank you @slippack for letting me know about the unglazed tile- makes sense ! It is def not a diy- hope my filers do a good job!

You need the Daltile Keystones custom patterns for that. https://s7d9.scene7.com/is/content/daltile/DAL_Keystones_TilePatternGuidepdf

I don't think shiny tiles that small are going to pose a slipping hazard. I have a shiny marble basketweave mosaic on my bathroom floor, and it's never caused any slipping. there is so much grout that it's not a problem. Larger shiny tiles on the floor would be.

I have polished hex tiles in my shower and I can confirm they are not slippery, due to grout.

Ahh. Thank you- tiny shiny tiles are ok. Is matte or polished more in line with the historical look?

The Keystones, linked above, have bedn msnufactured gor 80 years. They are in almost every NYC apartment building lobby of note. Note that these are the through body unglazed porcelain. And you seal through body unglazed porcelain before grouting.

Either is historically accurate

https://www.americanolean.com/products/mosaic/unglazed-mosaics

when I have visited restored buildings that had hex mosaics, they were ALWAYS matte because the color goes clear through the tile. Because they have a surface 'tooth' or micro texture they will grab dirt but they clean easily.

When I was doing commercial work, we always used them in hospitals and airports because they were virtually indestructible in the unglazed finish..

if i buy the unglazed finish... does the installer put something on top? or it's left as is + grout?

We have unglazed hex tile in our shower and it has been very easy to clean especially with the epoxy grout. I don't think our installer put any seal on the tile. As potter I can tell you good porcelain is fired to a higher temperature which makes it stronger more vitrified to absorb less water so it will not get a grungy as low fired unglazed ceramic tile which is often sealed. The added texture of more grout with the tinier tiles will also give glazed tiles fair slip resistance. With any tile make sure the clay body is close to the glaze in color. You don't want to chip a white marble like glaze and find bright red terra cotta.