That's right, I have received yet another note! Who passed it to me this time?
I think to the answer to the riddle (which I found just to late, but credits to xhienne) is:
My prefix goes vroom: auto
My infix you consume: tomato
My suffix break shelf: As Misha Lavrov noticed, this might mean that putting "a ton" of stuff on a shelf breaks the shelf.
I operate all by myself: by definition
Bonus picture of the riddle:
Partial answer: the following riddle appears...
... if you draw the lines that are missing in the patterns:
My prefix goes vroom
My infix you consume
My suffix breaks helf (1)
I operate all by myself
(1) Should actually be read "break(s) shelf"
Not my level unfortunately, so I leave this typical Riley riddle to true amateurs.