Contemplation or dhyāna sounds and seems similar to dhāraṇā (concentration), but is subtly different: while concentration is a one-pointed focus, contemplation brings about keen awareness without the focus.
While concentration requires to concentrate on one object, contemplation enable us to observe it without judgement, without attachment, instead contemplating it in all its colours and forms in a profound and abstract state of meditation. Therefore contemplation, instead of being something you actively do, it becomes a state of being.
The line between what one does (breathing , repeating a mantra or using a light visualisation) becomes blurred and the separation between you and whatever you’re focusing on disappears.
Just as the word yoga means to yoke or union with, during the practice of true contemplation (the state reached when we forget that we are contemplating or meditating), thoughts, emotions and desires subside and our state of doing merges with our state of being: the subject and object become one.