I was just wondering, what does it take for a new images to be moved into the permanent gallery?

Why did my image disappear from the site?
There is no promise that we will keep every image that is uploaded to the site. We try to keep every image for a minimum one month. If an image has been on the site for more than a month, we will make a decision on whether or not to keep it. The objective being to highlight the best images that are uploaded and to make room on the server for new images. If we did not do this the good images would be too difficult to find and the server would be too expensive for us to afford.

That's from the FAQ in case you were wondering. The images are moved to the permenant galleries manually at the discretion of the imagemods. A high c-index will usually indicate that an image is likely to be moved there, however it is not a guarantee.

is there a time period by which mods delete / move images, or does it get done as and when?

We try to leave the images in the New gallery for at least two weeks so everyone has time to see them. After that they are generally moved whenever a mod has the time to go through them all.

I see, thanks Sam.