Two woman wearing dresses are standing outside on the grass while one of them is holding a cup and saucer.
Two women in dresses are getting ready for the picnic.
Just because the women are outside holding a cup a saucer does not mean they are getting ready for a picnic.
We have no idea if they are getting ready for a picnic, they could be doing anything.
You can not infer they are getting ready for a picnic.