The most common and most likely answer to this crossword clue is the 5 letter word SWAGS
S
W
A
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S
Buddy explains!

The straight part
We know that "window-dressing?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case window-dressing? = swags.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SWAGS mean?
SWAGS noun- Initialism of scientific/speculative/sophisticated/stupid wild-ass guess.
- (window coverings) A loop of draped fabric.
- A low point or depression in land; especially, a place where water collects.
- To (cause to) sway.
- To droop; to sag.
- To decorate (something) with loops of draped fabric.
- To install (a ceiling fan or light fixture) by means of a long cord running from the ceiling to an outlet, and suspended by hooks or similar.
- Style; fashionable appearance or manner.
- (thieves' cant) A shop and its goods; any quantity of goods.
- (thieves' cant) Stolen goods; the booty of a burglar or thief; boodle.
- Handouts, freebies, or giveaways, such as those handed out at conventions.
- The possessions of a bushman or itinerant worker, tied up in a blanket and carried over the shoulder, sometimes attached to a stick.
- (by extension) A small single-person tent, usually foldable into an integral backpack.
- A large quantity (of something).
- To travel on foot carrying a swag (possessions tied in a blanket).
- To transport stolen goods.