I can see it, and the properties are that it is a bitmap image. Did you put it there? (in other words, its not from the TF?) If you put it there and it is streaming from another source, such as photobucket, etc. then I would say that POSSIBLY the bandwidth from that source is being used. if you uploaded it directly from your computer, then the image properties may be such that it isn't loading properly, and thus the red "X"
If it's from Tag Fairy, I have expreienced that once in a while. sometimes the image that TF puts in your avatar area dosn't load, or that server that holds the image may be busy at the time you sign on! and the image cannot load, so the program just moves on and you again, get the red "X"
If you can see it, and some other people can't, they may not have the plug-ins required to view that particular type of image. or possibly they need more RAM to store that image for loading....OR they have pagefiles set too a smaller amount and it is cutting the Bitmaps. OR they have security software set that rejects certain images as data can be hidden inside them (a virus?)
in other words, it could be for many reasons.
(or maybe the Tag fairy is messing with you!!!)