I'm on a retina 13" MBP and the suggested tiles appear very pixel-y. Turns out they aren't retina-friendly. They should be double the size to work with retina devices. Here is a screenshot: https://www.dropbox.com/s/53idnormbdq2cxg/Screenshot%202015-06-04%2012.59.41.png?dl=0 This happened for the MDN tile (attached) and for the Firefox for Android tile.
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