To extend the documentation example, wouldn't you just have "my-div-id-sibling" already and call
display("my-div-id", face);
display('my-div-id-sibling", someOtherFace);
Like almost all discussions that use language like "good API" or "bad API" this seems to me entirely personal preference. Personally I find anything where I end up having to call appendChild() myself a bad API.