A nightgown is submissive, pajamas are authoritative, representing a situation at home
The color of the evening gown has great symbolic importance.
As a “wishful dream”: a longing for social advancement. It may be that there is happiness about reaching it, or a failure to know how to handle it.
Folklore: The more beautifully the woman is dressed, the worse the omen.... Little Giant Encyclopedia
If you see others thus clad, you will have unpleasant news of absent friends. Business will receive a back set.
If a lover sees his sweetheart in her night gown, he will be superseded. See Cloths.... Ten Thousand Dream Interpretation
If the dress is white, it suggests that you want to appear pure and angelic toward others.... My Dream Interpretation
Depth Psychology: The nightshirt or nightgown indicates hidden erotic desires and needs. It could also point to your own character and that of the people wearing the gown.... Dreamers Dictionary
To take somebody in tow. But also dignity, splendor, and worship. Often this image refers to Bride. Sometimes it may suggest time is “dragging,” addressing the subject of patience.... Little Giant Encyclopedia