Rotom possessing any device other than the usual ones (in other words, any device except an Electric Fan, Refrigerator, Microwave, Lawnmower, Washing Machine, Pokédex, or Cellphone).
If Rotom is seen possessing a device before it could be done in actual Pokémon media, it still qualifies as this tag. Example: In post #2110931, Rotom is seen possessing a Pokédex, but this fan work predates the actual Rotom Dex from official media.