One of the motifs I found in the play was "breaking boundaries." Boundaries, in this sense, could mean multiple things. Staying in character is a boundary that is broken in the third act when the play they're performing is basically falling apart. Being in relationships with either multiple people or with people normally deemed inappropriate in our world is a boundary that is broken throughout the entire play. Selsdon undressing Dotty to find a contact is a boundary that furthers Garry's already very present anger.
We often think of boundaries in terms of "lines we can't cross so we don't screw up." But even if this play were to be one that broke the fourth wall instead of putting on the illusion of real life, the breaking of the fourth wall would be the breaking of a boundary.
As for a tag line, one word that comes up in the play the most often is "Sardines." My idea behind using this is that, though they are generally referred to as fish, sardines can also mean "describing any situation where people or objects are crowded together" ("Sardine"). This play seems to have the people and objects in a very sardine-like situation. In the second act, both the play in the script is happening "on stage" as well as the events back stage with the relationship drama. It almost seems as though the characters are both themselves and the character they're portraying, causing the perceived amount of people to double and begin crowding. This crowdedness drives a lot of the play to be portrayed as it is in the script.
"Sardine - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. Web. 18 Mar. 2013.