soft/hard launch
These are marketing terms. The soft launch refers to the release of a product with no publicity campaign except perhaps a small one directed to a restricted market. It accompanies the trial of a product before a major release. The hard launch employs the full PR weaponry and is directed towards the whole market.
These terms are now being applied to the release of information on social media about one’s relationship status. The soft launch is careful, subtle, sometimes teasing. You might put up a picture of two plates on the table at a restaurant, two pairs of shoes by the couch, you might even go so far as to have a hand or the back of the head or a shadowy glimpse in the picture. You provide enough to let everyone know that there is an SO (significant other) in your life.
The reasons for the softly softly approach vary. Perhaps you are still not quite sure of the depth of feeling in the relationship so this soft launch can be a way of testing whether you are in a situationship or a relationship. Perhaps you just like being mysterious for a while until you reach the reveal stage. Perhaps you are gently introducing others in your life to the idea that you have moved on.
The hard launch leaves no one guessing. Both people are clearly seen in the picture. The level of intimacy indicated varies depending on how discreet or outrageous the couple wish to be.