In answer to your kind questions:
I think a few more pictures of offending tiles would help a bit more...
The other tiles look like the ones in the picture posted earlier.
as you said they're in the shower area, was it tanked prior to tiling?
Yes, a BAL shower kit was used.
From one pic its hard to say was there any waterproofing what is the substrate and what adh was used is it a shower area and finally do the tiles absorb water (may cause pic framing)
Waterproofing = BAL shower kit
Substrate = plasterboard (skimmed)
Adh = BAL Green Star (I asked for White Star)
Is it a shower area? Yes and there are exposed edges (like the one in the photo) in the shower area.
Do the tiles absorb water? I don't know: the tiler told us not to use the shower until next Tuesday.
Picture framing? Sorry, I don't know what that means.