With the setting of a bakery, the encounter of Miss Martha Meacham and the middle-aged German man is initially one of chance, as well as one that is brief.  Each day he comes for stale bread which he purchases and then immediately departs the bakery, so there is little opportunity for Miss Meacham to speak with him.  For this reason, she contrives the posting of a painting so that the German customer will notice it and react.  In this way, Miss Meacham may be able to determine if he is an artist as she has suspected.  The next day when the man enters the bakery, he does, in fact, comment upon the painting; therefore, Miss Meacham believes that he is a starving artist. In her sympathy and interest, the baker slips some butter into each loaf intending a kindness.  But, the irony is that the buttered bread destroys the German draftsman's drawings, causing him financial ruin.  He returns to the bakery, cursing the baker.

Clearly, the bakery as the setting controls the actions of the plot.  Only once each day does the draftsman come, and Miss Meacham can but guess at what he does in his obvious state of penury.  And, since she only sees the man briefly each day, she does not get to know him well.  That there can be the misunderstanding between Miss Meacham and the draftsman is entirely possible within the setting, and, of course, that she can dash all his hopes for success with her simple loaves of stale bread is also possible in O. Henry's ironic short story.