The transparent shark both connotes Tom Stenton (who in appearance is compared to a shark and who wished to bring this shark back to the Circle and have it fed) and more importantly the Circle itself. It is transparent, but that doesn't stop it from devouring every defenseless thing in its path, which is what the Circle may turn into soon after Completion.
The Tear (Symbol)
Mae, at various times in the novel, feels a black tear inside her accompanied by millions of "drowning screams." She debates whether this is caused by knowing too much or too little, at times making a decision one way or the other but always feeling very clear about her decision. This indecisiveness illuminates her confusion with the way she feels, and the tear itself is complex in that it forces her to turn inward momentarily (rather than presenting herself outward to viewers), but also has her hear what seems to be the screams of millions of others inside her, as if she cannot get away from her connection to the masses.
The Chinese Sculpture "Reaching Through for the Good of Humankind" (Symbol)
The Chinese sculpture is an ironic symbol of the Circle's omnipresence that allows it to reach into the lives of its users. Circle employees seem to find it obvious that this is a positive symbol of the Circle reaching out with a helping hand, missing the fact that both the in-text creator and Eggers himself mean it satirically, menacing even (or especially) in its giant transparency.
Stewart's Storage Unit (Symbol)
Mae's fascination with Stewart's Storage Unit far in the basement of the Circle is symbolic of exactly what all the sharing she and others have been doing amounts to. It physicalizes the amount of information one can put out, but its storage in a dank and secluded place demonstrates the sadness and wastefulness of attempting to share everything with everyone.
Mae's Screens (Symbol)
Mae is given two screens on the day she begins work at the Circle and is flattered to have so much technology all to herself. Throughout the novel, she slowly amasses 9 screens (11 if one counts her 2 bracelets, one with health information and one displaying her transparent broadcast) which constitute the number of "layers" that have been put on her. These show a progression of time and her rise through the ranks of the Circle, but more than that they demonstrate the information overload Mae is exposed to constantly.
The Circle Questions and Answers
The Question and Answer section for The Circle is a great
resource to ask questions, find answers, and discuss the novel.