Pics of Gotland being treated as a starter ship (and/or childhood friend character or similar role), gas-lighting, hypnotizing or drugging other people into thinking she's a starter ship, or straight-up bending reality or messing with the timeline in order to retrocausally become an actual starter ship.

Unlike most foreign ships (and some Japanese ones, even) Gotland's in-game lines have her drastically transition from a semi-formal introduction line into acting completely chummy with the Admiral and the rest of the naval base (being willing to accept or receive displays of physical affection, playing pranks on the other shipgirls, etc.), as though she's a long-time resident of the base and is on casual-to-intimate terms with everyone.

This led initially to art being drawn of Gotland being an honorary starter shipgirl, or as a 'waifu character' with childhood-friend vibes. This soon rapidly mutated into Gotland being depicted as outright brainwashing the Admiral (and other shipgirls) into believing the above, then evolved further into Gotland being treated as a reality-warper or time traveler with the ability to alter history to turn herself into an actual starter ship (or childhood friend/mother figure).

See also:

• Pixiv equivalent tags: '名誉初期艦'(Meiyo Shoukikan, 'Honorary Starter Ship') OR 'ゴト島さん' (Gotshima-san)