If it's a book I have heard about it, that has been recced and that sounds interesting, I don't care (much) what the cover looks like. (Apart from Baen covers, which are dreadful even for ebooks where cover shouldn't matter a lot as far as book enjoyment goes.)
If I am just browsing, covers matter - unprofessional-looking covers indicate that this may be a book by a self-published author or small publisher who doesn't put a lot of effort into other parts of the book either; professional-looking covers tend to give me some expectations of genre (e.g. naked male torso on cover - romance, don't buy; semi-naked male in leather pants on a fantasy-ish looking cover - probably paranormal romance, don't buy; young woman in leather clothes, holding a weapon - probably urban fantasy, worth a closer look; dragons on cover - traditional fantasy, don't buy).
A cover featuring anime style art, if I'm just browsing (either in a physical bookshop or a general "new releases" page online) tells me that this is probably a manga / anime / comic book thing, which I'm not interested in, so I'd move on without taking a closer look at the back of the book / the book's page.