Winona's G.E.M.erator, alongside her other gadgets and the Engineering Tab, was introduced in her Character Update as part of the character overhaul for Don't Starve Together.
According to Rhymes With Play #228, Winona's G.E.M.erator was supposed to be a battery, but was rather named a G.E.M.erator partly because of the wordplay.[1]
ギャラリー
Winona's G.E.M.erator's placing animation.
The G.E.M.erator's crafting icon.
An early concept version of Winona's G.E.M.erator from Rhymes With Play #228.
Earlier concepts for Winona's G.E.M.erator from Rhymes With Play #228.