Enlightenment is the complete development of all positive qualities and the complete elimination of all negative qualities (all qualities based on ignorance). As such the individual experiences cessation of ignorance and their behavior is focused on freeing all beings from samsara and samsaric thinking.
The OP asks what it is like, not a textbook description of it's meaning. A metaphor, for example, would be less abstract, but still an abstraction of course.
I would argue that what I wrote isn't a textbook description because all people experience negative mind states and most people experience positive mind states. So we can imagine what it would be like to have infinite love and compassion based on that alone. Then we can add in infinite wisdom.
Or we can read the life of the Buddha and other beings we consider to be enlightened.
To answer the question well you would need to have experienced enlightenment and relate that experience,
No, it's sufficient to take a look at their qualities and relate our behavior to that. But if we say an enlightened being has the quality of infinite love, kindness, compassion and wisdom then it can be difficult to see them interacting in the everyday world in difficult circumstances because we can then idealize their behavior and circumstances.
or rather, honestly say what enlightenment means to you personally.
This is problematic as many people break enlightenment down in terms of that they imagine as objective observation and relate this to perceptions of interactions with others. But enlightened people might not have appealing or charismatic personalities. Chatral Rinpoche for example was alleged to throw rocks at people at one point. HH Penor Rinpoche was also said to be capable of being physically rough with his monks should some real infraction take place. I saw a major lineage head speak forcefully at a person and HHDL has just reaffirmed in an interview that he can have a temper.
Stray away from the qualities and we can get lost in our projections.
_________________Kirt's Tibetan Translation Notes
"Only you can make your mind beautiful."
HH Chetsang Rinpoche