To be sure, for a giant like Apple, Target's sales are "just a blip," said Gillis, "just a little tiny data point across the global landscape."
But the trouble at Target, on top of everything else, could raise the stakes ever higher ahead of the next iPhone, rumored to debut as soon as next month.
"There's some data points out there that are collecting that show that this iPhone 7 may not resonate with consumers the way that investors are hoping it will," Gillis said.
One such data point is recent research about China, where Apple's smartphone growth dipped nearly 32 percent over the past year, according to IDC. That put Apple in fifth place in terms of market share, by IDC's estimate, as local vendors saw growth explode.
That's a concern in a slowing overall smartphone marketplace, Gillis said.
"It's not likely that [Apple's] growth is going to continue forever," Gillis said. "This market could stall out."
If the next iPhone is a similar form-factor and iteration of prior models, it could risk losing its status as a "fashion icon" Gillis said.
"If you think of what company in tech is as close to a fashion status symbol, it's Apple," Gillis said.