I wondered the same, but then released that he's probably blown a brick out when drilling a hole for a data cable and then after job is complete has stuck the broken bit back with clear silcone
Thanks for your (probable) explanation.
While silicone will "stick" a small piece of broken brick back on, for cosmetic purposes, it will not provide much strength if this
is required.
In such cases Epoxy Resin is a much better solution, but it would not be a good idea to fix any cable with it at the same time!
On occasions, I have made a mistake and drilled a hole in brick for a wall plug with the hole being slightly too large for the plug used and the fixing was "loose" as a result.
Epoxy Resin is a very permanent "fix" in such situations - and Epoxy Resin Putty might also be used.
On the wall of a neighbour is an example of where such a "fix" is required.
All that is necessary is some Epoxy Resin in the holes in the bricks, reinserting the wall plugs and rescrewing the fitting to them when the Resin has set.
If I ever got to know any who reside there I would offer to fix it, since it "irks" me every time that I see it.
Obviously, the neighbour does not use this light and the tree is growing so that I soon won't see it.