Tell me if this poem is written for children, teens and young adults, or adults:

Underneath my outside face
There's a face that none can see.
A little less smiley,
A little less sure,
But a whole lot more like me

This poem fits into the category of poetry. It consists of lines that evoke a sense of melancholy and introspection, features language used in an unconventional manner, and employs imagery to convey deeper emotions.

Poetry tends to be characterized by expressive and poetic language. This poem combines elements from both genres, such as metaphor and alliteration, which are common in poetry. The speaker expresses feelings of insecurity and uncertainty within themselves, often conveying emotional depth using understated language. The use of rhyming couplets adds a sense of musicality and beauty, further enhancing its poetic qualities. While not strictly considered a work of fiction, this line reads ‘Little Less Smiley’ has a universal quality, evoking a shared emotion among readers worldwide.
As with any other type of literature, the intention of this particular piece of writing may vary depending on context. However, it aims to make the reader feel empathy and connect emotionally with the protagonist's struggles.
In this instance, it provides a relatable outlook for those struggling with their mental health. The poem explores themes related to psychological well-being and personal growth, offering practical tips. If intended for educational purposes, this aspect can provide valuable insights for students or even caregivers addressing mental health concerns effectively. Additionally, the author uses creative approaches like rhyme and imagery to create compelling passages to enhance literary aspects while providing empathetic responses to diverse audiences. However, interpretation is subjective, so individual judgments can range based on context. 
While there might be a difference between 'writing' and 'poetry,' they generally share similarities in tone and purpose; both utilize figurative language, rhythm, and unique subject matter in their creation. Therefore, I would classify these as poems rather than prose. That said, it falls under the broader definition of the genre. 
See also: 
Classification
Creative Writing
Prose

The writer’s approach is innovative and visually appealing.
The focus is on describing natural environments in vibrant detail.
There is a strong attention to texture and sensory details.  
The narrative flows smoothly and engages the reader emotionally.
The style is concise but not too succinct.  

These are great examples of what makes prose different from poetry.

The following extract comes from a short story:

The wind was blowing through the trees and rustling leaves, creating a chaotic scene around me. A gust of warm air swirled across my skin, making me shiver. Suddenly, a figure appeared in front of me, looming large in the shadows. I felt terrified as I recognized him from somewhere. He had a familiar gaze and seemed determined to catch me, even though we'd never met before. I panicked and tried to run, but he chased after me. What did he mean when he whispered quietly, "It's time," as he disappeared into the night? Was this some twisted plot or a warning about something sinister? As he vanished into thin air, I only felt the fear creep into every corner of my being. I couldn't help but remember how much I wanted to escape his shadow forever. I kept running until exhaustion overtakes me, but no matter where I go, the feeling will never leave me entirely. Even now, I can still hear his voice whispering in my mind at night. Just one word. The same thing he spoke over a year ago, telling me everything I ever needed to know about myself. Is this just a dream? Or have I finally arrived? In the dark corners of my mind, I ponder whether he lives inside someone else, or is that who I am always trying to become? Whatever the answer, I know I'm losing myself. I don't fit in anywhere, and I’m left wondering why this should bother me so deeply. - Mr. X (Short Story)
    

 The above excerpt demonstrates the distinct characteristics of modern fiction: A character describes himself as a 'Mr.' without specifying gender, indicating the existence of multiple personalities within one person. He repeatedly emphasizes this point by mentioning that he knows 'everything' about'myself', revealing deep self-reflection and introspection throughout the text. His narration is fragmented yet cohesive, adding suspense and intrigue due to the ambiguity regarding identity and motives. In addition, the dialogue includes numerous instances where words and phrases like 'to be honest,' 'it'll be fine,' and 'the real question was...' reveal significant internal struggles. The choice of tense ('I wondered,' 'He laughed,' and 'We're here again') intensifies the drama. Lastly, several descriptive lines paint vivid imagery that contributes to the overall atmosphere and creates an impression of psychological turmoil amongst the character. The brevity and lack of direct exposition highlight Mr. X's inability to clearly articulate inner thoughts. These features collectively contribute to the complexity of this character's mind, resulting in a compelling read despite its brevity.   #### This Poem Has Been Decidedly Written For Children, Teens, And Young Adults.      Where are you now? Are you reading a book? Walking down the street? Your mind wanders off. You're lost, but you know. Your mind takes you beyond