A rose is a device with very small holes in it that fits onto the end of a hosepipe or watering can. The water comes out of the rose in a fine spray so that you can water plants.
PHRASE
尽善尽美;尽如人意
If you say that a situation is not a bed of roses, you mean that it is not as pleasant as it seems, and that there are some unpleasant aspects to it.