There is physical tension, like a spring that is wound up too tight or a rubber band that is stretched too far. The physical senses seem narrower, but it is more of a narrow focus that is harder to notice when it is happening. Peripheral vision, as an example, tends to not work as well. Mentally the same sorts of thoughts tend to repeat and more quickly. Emotionally it feels almost like holding the breath; there is tightness and pressure like and effort to contain something. And then when the craving is being satisfied there is an enormous release of tension as all of these effects wash away and the senses open up again and the body relaxes.