(Hook thesis statements) Is this imagery?:

Many students, wether through inaccess or forgetfulness, have to sit through class with empty stomachs and try to pay attention while ignoring their hunger. ​

Imagery paints a picture; it’s visually descriptive. So while this isn’t the most descriptive, it does give the image of a classroom full of students. I’d suggest maybe adding that they’re sitting at their desks, (while we know it’s there, it’s better to tell for the sake of creating a picture) and maybe give their expressions- longing, hopeful, etc. Hope this helped!