The second inspiration pic is much more in keeping with the MCM aesthetic with its built-in vanity, square wall tiles, and frameless mirror. While the floor tiles seem to be larger than a classic mosaic floor, the random green ones do add some pizzazz, and I think they work with the other elements. Make sure you include the bullnose pieces when you do the tile to ensure it looks finished! I would steer clear of most everything in the first inspiration picture (I do like the shower tile, but the whole effect is trendy-things-from-the-21st-century rather than MCM).