Background
GK1
Bruno's Florist shop lies across Bourbon Street from St. George's Books. He is interested to obtain the painting "Three Snakes in a Skull", however Gabriel Knight is less than reluctant as he doesn't like Bruno much, and the painting is the only one he has from his father.
Day 1, Bruno enters the shop on Gabriel's return to the book shop. Gabriel can push him away, insult him, or try to sell him the painting (but Grace steps in to stop him).
On Day 3, after learning about Voodoo Masks, and Willy Jr. at Dixieland Drugstore Gabriel learns he needs $100 dollars. It is the first day Gabriel is able to sell the mask, again Grace will try to interfere but Gabriel has the choice to proceed with the transaction. He gives Gabriel a crisp Benjamin.
Grace who cares for Gabriel ultimately buys the painting back from Bruno and rehangs it back on the wall.
See also
Behind the scenes
Bruno's appearance is somewhat random on Day 1, he might appear after doing nothing for several moments, or by coming back to the bookstore later, and also waiting and doing nothing.
He does not seem to appear on Day 1 in the remake.