hi may i know where you get the brick tiles ? approx how much psqft yeah ? these are wall claddings right ?

I don't remember the brand, just go to shop that's selling tiles and tell them you need waterproof sealant for bathroom. Without sealant, your raw cement will release dust, if your contractor don't have the experience then I'll guess you need to find someone else.

Will it come out as glossy after applying the waterproof sealant?

No.