A person is squatting down near buckets, holding something in one hand.
Someone is dipping a sponge in a bucket of soapy water.
A person holding something in one hand does not imply that it is a sponge, or that they are dipping it into a bucket. Buckets can contain substances other than soapy water.
The fact that someone is holding something does not mean the item is a sponge or that he or she must be dipping a sponge.
The buckets may not have contained soapy water therefore a person would not need a sponge.