If you would like to submit to the Gallery, please comment on
these works.
In simple terms, state the things you like and explain why, state the things you dislike and explain why, state the things the artist could improve on and suggest ways to improve.
That's just the basic foundation and should help you form your comment. It's not a 'set' rule, but that's what we encourage people to include in their comments. Do it well enough and you will easily pass 100 words.