I'm not certain it can be said that jhāna itself extends to daily life after meditation, with all the different interpretations of jhāna going around.
At the same time, consider the following excerpt from AN 3.63:
“Here, brahmin [...], I collect some grass or leaves that I find there into a pile and then sit down. Having folded my legs crosswise and straightened my body, I establish mindfulness in front of me. Then, secluded from sensual pleasures, secluded from unwholesome states, I enter and dwell in the first jhāna, which consists of rapture and pleasure born of seclusion, accompanied by thought and examination. With the subsiding of thought and examination, I enter and dwell in the second jhāna [...] I enter and dwell in the third jhāna [...] I enter and dwell in the fourth jhāna [...].
“Then, brahmin, when I am in such a state, if I walk back and forth, on that occasion my walking back and forth is celestial. If I am standing, on that occasion my standing is celestial. If I am sitting, on that occasion my sitting is celestial. If I lie down, on that occasion this is my celestial high and luxurious bed”
So, the Buddha is describing a certain quality persisting after the meditation, referring to it as "celestial" (dibba). This might be the trait your are asking about.
Note also that, if after samatha meditation one were "just like before the meditation", then for every single meditation, the difficulty to practice samatha would be the same. However, it's expected that it gets easier with time and practice.
I would claim it gets easier because the mind acquires the qualities of samadhi, even though arguably these qualities may not be in their most potent state -- say, during jhāna.
This might not be surprising from a neurological point of view, since the chemistry and behavior patterns of the brain are bound to change with any kind of repeated practice.