Row 24 on BA
's 757s has 2 windows on each side...
There's a toilet ahead of the L3 and R3
doors, row 24 is the last row before those toilets - both the seat backs of row 24 and the cabin windows go right back to the bulkhead.
View Large View Medium
Photo © Jason Taperell - AirTeamImages
If you see in the photo there's just one missing window ahead of the L3/R3 door which corresponds to the location of the toilet.