What Tail?

Here's Sunday's Nancy strip by Olivia Jaimes...

Setting aside whether you find the joke here funny or not, why did Jaimes opt to place the tail of the only speech balloon in the entire sequence behind the painting, obscuring it almost completely?

My initial guess was that it was an accident perhaps from creating the painting image separately and copy/pasting it into the space so she could get the perspective right. But if that were the case, why not use the same art throughout the entire strip? It's clearly a different image than the one that is repeated throughout the remainder of the strip. If you drew it larger to do the perspective on the production side, you'd have it set and ready to copy/paste throughout the rest of the strip, so why go to the extra effort of drawing it a second time?

And it's not like there was other art in the background of that first panel that Jaimes was trying to avoid covering. It's literally just a solid, flat color for the whole panel's background. That tail could easily have been place just straight off the left side of the balloon. Indeed, that would have been even easier to draw since it would not overlap or interact with literally anything else in the panel.

It's just a really strange decision, and I can't fathom why an artist would make that choice. The only rationale I can possibly come up with is that she's got a set of pre-drawn speech balloons that she copy/pastes into place and was so pressed for a deadline that she just grabbed the first one she could get a hold of. But that seems like quite a stretch; that would have to be someone-from-the-syndicate-on-the-phone-with-her-while-she's-finishing-it-because-it-was-supposed-to-have-been-sent-out-a-half-hour-ago levels of being up against a deadline. Which strikes me as really unlikely but, like I said, that's the only explanation I can come up with. Any other ideas?

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