Liquid Music’s transport buttons in MaxForLive mode (Play, Stop) control Ableton Live’s clip’s transport buttons. When you press [play] in Liquid Music, Liquid Music tells Live’s selected clip to start Playback. If Live’s global transport is stopped, the clip then tells Live’s global transport to start playback as well. This is identical to the effect you’d get if you were to press play on a clip directly in Live!
Same thing with Liquid Music’s [stop] button: It sends a Stop signal to the clip, which stops playback of the clip in Live – however, that does not move up to Live’s global transport. (Again, identical to the effect you’d get if you were to press stop on a clip directly in Live.) The reason it works this way is because the Liquid Music arranger is editing a clip, so we figured the transport controls should also control the clip’s transport controls.
Additionally, it lets you “perform” Live’s clips directly out of the LM UI without having to switch back and forth. If you couple this with using the “Clip Selector” panel (in the Molecule Toolbar at the bottom of the LM window (opened by pressing “MT” in the top right of the screen), you can navigate and control all of your LM’ed clips directly from LM.