The front of the DS414 Slim is shown in the image below.
The housing is a matte charcoal color that does a good job of masking fingerprints. On the bottom right the model number is listed. Also on the front there are indicator LEDs for each HDD and for each LAN port. It also has a convenient USB 3.0 port front and center.
Unlike the DS415+, the power button and Status LED are not located on the front. These are located on the left side of the unit towards the front as can be seen in the picture below. Having the power button and LED on the side is OK but I would prefer to see the Status light moved to the front as many people may have limited visibility to this LED. The other side of the device just has the Synology logo printed on it.
On the back of the unit there is a pair of Gigabit RJ-45 ports, DC power connection, another USB 3.0 port, reset button, and lock. This is also where you access the (4) drive trays. Each drive slot has a number printed on the main housing. While they do provide stickers to number the drive trays I would have preferred these be factory stamped too. But I understand the costs involved to have each tray be different might not make sense.