I see code like this that works:
show3D[graphics_] := Show[graphics, {ImageSize -> localImageSize}]
It works similarly if the list of options contains more than one option; and it works if the list of options contains zero options.
Normally, I see options strung as individual arguments at the end of the list of arguments; not inside any list:
show3D[graphics_] := Show[graphics, ImageSize -> localImageSize]
That's what I've seen in many examples in the documentation, iirc. Does putting them inside a list make any difference? Thank you.