You can see a mouse cursor in the video. Someone is manually zooming in and following the plane, likely while reviewing the footage.

Rows have numbers, columns have symbols. The person is supposed to sit in the seat in row 79, column ‘bumblebee’ or whatever.

I’d assume the arrows move the person to a different seat. The screenshot shows the solved captcha.

Not to defend it, but it looks like at least two of them have a badge hanging around their neck.