PNG generates smaller files than GIF and is overall a better designed format (IMNSHO). It's my default format for taking screen captures, and I only just now discovered that I had to go back and convert them all to GIF to upload them. Quite annoying.
PNG has lossless compression - this would simply not work with a size max of 150k as we have here. A JPEG would look far better than an equivalent sized PNG when it's a photograph being displayed.
Yes, I'm referring to screenshots. I recently made a bunch of captures of various histograms and settings for a mentorship thread, which is when I discovered the GIF-only restriction.
