In the interests of conserving server space and for quick download times, I strongly suggest you convert any screen images to a compact format such as jpeg (jpg) before posting. Also, use your image editing program to cut out the portion of the screenshot of interest and make that smaller image the one you post.
It's really annoying to see huge images in which most of the screen real estate is not of interest.
Refer also to the "Important Announcement" by Thunderfall at the top of the threads list for some more info.
(Jeez, I'm sounding like a moderator, sorry!)