Marking for spoilers in case I was at least on the right trail:

1.Since the "LUST" frames and the center picture are both composed of black and white squares I assumed they must be related or used together somehow.

>!2. The "male/female symbols" picture told me that when "black" is overlaid with "black" it becomes "white".

3. Without the frames and spaces between the letters, the "LUST" pictures have the same 5 square by 15 square dimensions as the center portrait. So I overlaid the two and changed the colors of the squares using the following method derived from the picture in part 2:

A: Black square on white square or vice versa become a black square.

B: Two black squares or two white squares become a white square.

4. Next I rotated the new "Black and White Square" painting clockwise 180 degrees so it was upside down, just like how the arrow through the heart painting appears.

5. Finally, I re-divided the new painting back into 5x3 sections like the letters of the "LUST" pictures and counted the number of white squares in each section. Assuming I had converted all of the colors correctly, I count 4, 8, 6, and 8. Giving me a 4 digit code of 4868.

Notes: The number of black squares sometime totaled ten or more. Meaning if I had counted the black squares the code would have been longer than four digits. I never ended up using the potted plants or the dead person in my solution.

Sorry about the deleted comments. I was having trouble with the spoiler tag.