The “chunk of land” in question has no name, and is therefore not a game space. If it were connected to United Kingdom (which it isn’t), the rules for islands wouldn’t apply, as United Kingdom would not then be “a single territory surrounded entirely by one or more sea zones” (Eire would keep it from being so). In any case, it’s a moot point, as neutral territories may not be entered in this game, and there are no sea zones that touch the unnamed land mass that don’t also touch United Kingdom.
In 1940, the same land mass is connected to Scotland by virtue of the UK emblem straddling (and obscuring) the sea between them, as CWO Marc pointed out. In this case, land units can move between Eire and Scotland without the use of transports, and it is relevant, as neutral territories are not off-limits in that game.
Hope this helps.