Or does it actually cheer you up? If it cheers you up, why does it cheer you up? Because it's a touching tribute to human optimism, because something cheery really is cheery wherever it is, or because it's incongruous and incongruous is funny?
ADDED: This is the Clark Street subway station in Brooklyn Heights:
The first stop in Brooklyn on a west side train is Clark Street. This island platform station is very deep (approx. 100 feet below the street) and has rounded side walls indicating the deep bore construction of the under river tunnel. Access to the street is by elevator. The platforms have sailing ship mosaics and a large "Clark Street/Brooklyn Heights" mosaic name panel. The street level fare control has a directional mosaic to the Hotel St. George.