Final answer:
The phrase 'artistic tendencies' humorously characterizes the mess created by Allen as a form of art, reflecting Aunt Ella's mild reaction rather than dismay or a literal artistic endeavor.
Step-by-step explanation:
In the passage, the phrase artistic tendencies is used humorously by Aunt Ella to describe the messy situation caused by Allen. The eggs that were once neatly contained in a basket are now scattered across the kitchen, which Aunt Ella interprets as a form of artistic expression. Instead of showing frustration, Aunt Ella's mild-mannered reaction frames the chaos as something creative and worth capturing with a photograph.
It suggests that Allen, through his play, is displaying a raw and unintentional form of artistry, using unconventional materials such as egg yolks and shells. The phrase is not meant to be taken literally, as there are no careful and deliberate designs or unique materials typically associated with art. Instead, it is an affectionate and slightly sarcastic way of responding to the mess Allen has made.