Different between small and giant gifts?
AFAIK, Smaller gifts give smaller amounts of the Wintersday tokens (socks, sweaters etc.) and they also drop snowflakes of different tiers (Small gifts will drop Tiny and Glittering Snowflakes, for example). I’m not sure what the odds of getting things like the Grenth/Dwayna recipes are like from smaller gifts, or even if they drop at all.
AFAIK – tonics, bells etc – same chance. Difference is – small gits for low level players in low level zones, so you will get low level craft resources, but same festive items.
English is not my native language, sorry :<