I left some text-bubbles untranslated to build toward a specific gag where Yotsuba, upon welcoming Fuuka into her home, butchers a stock polite-phrase beyond recognition. Keeping her jumbled speech here in the original Japanese, and rendering it as "[unintelligible]" in the form of a caption felt like the funniest way to translate this gag with respect to the original context. In order to do it properly, there had to be some other instances of untranslated text-bubbles with captions in order to introduce the idea and build the expectation.
Thanks for the question!