Shower Curb Penetrations
There doesn't seem to be anything out of place there.   The shower curb is there to keep water from exiting the shower.   The silicone is used so that water doesn't go under the bracket.   There isn't much the silicone is doing as waterproofing, although it is keeping the bracket from being damaged and maybe a tiny bit of water in.    There is nothing that concerns me in that photo.