Rocket Spanish Community

In the conversation, it emphasises "cuadra/s" meaning a block, with "cuadro/s" meaning a picture. In the quiz it seems to use "cuadros" for block - is that a misprint?

Yes, I think it is. In fact, even the lesson itself contains that same misprint in the following directions:
"derecho dos cuadros, a la izquierda dos cuadras-no, una cuadra, y de allí al final de la calla están."
And, as you point out, two questions in the quiz also contain this error.