Most of you experienced Gimpers will know this but I discovered this filter only recently, because GEGL has not been used widely yet. GEGL has different filters . I urge the newer members to explore these filters. This is an example for a "tie dyed" shirt. A fashion statement of the 70's. I had several tie dyed tshirts (which I dyed myself with food dyes and salt) and tie dyed silk neck ties (which I bought).
Start with a 640 x400 canvas or larger and render with clouds plasma (filter| render| clouds| plasma and make it as gentle or busy as you like. Busy tends to have more definition with the filter.
Then go to Tools| GEGL and drop down to the mirrors filter. And play with the settings . The settings apply imediately. When you get to something pleasing, save it.
Alternatively start with a well defined (sharp contours) eg a large image of Wilbur and play around or do another plasma render and use the Distort| mosaic filter to develop a sort of honeycombed image before applying the GEGL mirror filter.
This is not a very useful filter unless you are after a mirrored or somewhat kaleidoscope effect but it is a nice filter to play with if you just want to experiment. By using the zoom slider to a minimum you can get some nice textures. I did not include this step.
Have fun and dont take it too seriously.
Cheers Wbool63