The most common and most likely answer to this crossword clue is the 6 letter word INSETS
I've seen this crossword clue in The Times
I
N
S
E
T
S
Buddy explains!

The straight part
We know that "Pictures" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pictures = insets.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 INSETS mean?
INSETS noun- A smaller thing set into a larger thing, such as a small picture inside a larger one.
- Anything inserted.
- A small piece of material used to strengthen a garment.
- To set in; infix or implant.
- To insert something.
- To add an inset to something.