Compared to either Mary Shelley's novel or the later talkie version of "Frankenstein" with Boris Karloff as the monster, this would certainly have to be described as a bare bones effort - to be expected, I suppose, from this era and in a 12 and a half minute short.
The basics are there. Frankenstein discovers the secret of life and death (how, we're not told) and he uses that secret to create what he believes will be the perfect human being (the method of creation isn't explained) but that instead turns out to be only grotesquely human-like, rather than the perfect human. The monster (played by an actor named Charles Ogle) isn't as non-human as Karloff's version was, and there seems to be a certain sense of comedy about him. Eventually, this short becomes a story of jealousy. Frankenstein returns home to marry his sweetheart, but his monster haunts him and is overcome by jealousy against Elizabeth, Frankenstein's fiancé. The monster's demise wasn't sufficiently explained. Standing in front of a mirror, suddenly the monster disappears, leaving only its image, which also disappears after Frankenstein enters the room. The final scene shows the love between Frankenstein and Elizabeth, and I was left wondering if there really was a monster, or if this was all just a figment of Frankenstein's imagination, overcome finally by love.
This short (perhaps inevitably) left a lot of questions.