The left picture is the default water tap that came with the BTO. The nozzle is different from the usual washing machine tap, which has a larger hole and the screw groove at the side. However, there are many adaptors that are designed for taps like this because most BTO has this as the tap. However, the Samsung model we bought did not have the appropriate adaptor, and we had to either get a new adaptor or change the tap.
As you can see in the right picture, we changed the nozzle of the default tap. Apparently that is possible, so that is one option to consider next time we met with this situation again. The water pipe can now be attached to the tap direct and the problem is solved. Now to the red dot.
The red round object in the middle is a filter-like thing which can be found in the nozzle in the left picture. This is probably a requisite because I believe every taps in all BTOs come with such object so as to save water by reducing the amount of water flowing through. However, this became a nuisance for the washing machine because it likely would not start till the designated amount of water is reached. Hence this would not only not save water, but cause you to wait for 2 hours before the washing actually start. Disclaimer: I have not tried it with that yet, but reading through forums taught me to removed the red dot before connecting the washing machine, and I strongly encouraged you to do the same. You could probably leave the filter-like object in the other taps to really save water though. Save our Earth yeah!