dashel &  mangusu somehow out of nowhere got trapped in cell with no way to get out, they tried to communicate with the people passing by through the glass window asking for help, but those people see them as rare exotic animals in a zoo exhibit and saw their communicating for help as nothing more than just "cute animal gestures".

Just like in Happy Feet (before the girl tapped on the glass) where Mumble tried to communicate with the aliens (humans) about taking their fish, but all the "aliens" could hear were ordinary penguin squawking.

Original scene taken from Dash tiger's & Mangusu's "DaMit Morning (Episode 6) Blooper Video"
https://www.youtube.com/watch?v=XwLYnXBEWDo