Could I suggest putting spoiler tags on pictures as well, or if a post is going to be heavily spoiler ridden then saying so in the topic title. Furthermore listing the episode number that a picture comes from would be nice. For example I have seen Naruto from episode 1~150 but have not seen Shippuden, so a topic with Naruto Part I would be ok to see but not Part II (Shippuden). You get the idea : ) .
Anime-Forums have implemented a feature like that for quite some time now, where if you want to view the image, you click the button in the spoiler and the image is expanded.
It's awesome, plus prevents page deformation.