The phrase "small honorarium" means a small amount of money or compensation given as a token of appreciation or recognition for someone's services or contributions. Full definition
I received free products to use in my recipe testing and a small honorarium for my participation. (lemonsandlavender.com)
These individuals serve as volunteers but are provided with a small honorarium for the time and effort they put into the review process. (brightfocus.org)
Photographer: Document events such as opening receptions, artist talks, and performances; edit photos and send to Modern Fuel; photo credits and small honorarium will be provided (modernfuel.org)