I have known that reCAPTCHA is a project about digitalization of books, so those ugly, twisted, blurred, torn, broken, and most extremely inhuman images we got to be asked with those scanned images of tons of tons of books. I think that's great idea to benefit the project (helping digitalization) and the websites which uses it. We help input the text by proving that we are human indeed.
This was first time that I actually saw a photo from a book. It looks clearly to me it's a street number. If you have used OCR softwares, sometimes, they do detect text within an image even you ask them not to check text in image.
Last time, I was asked with some language I didn't even know what the language is, though I didn't have problems typing int those letters with diacritics.
Anyways, just one more thing to say, I really hate reCAPTCHA this day. Years ago, you don't even need to press the reload button for another image, I almost reload for another at first image these days and quite often that I can only tell what the two words are from third or fourth images. They have been getting terribly hard to recognize.