If you used fileize, it should be very clear.
When you upload a picture or an animation to fileize, it'll give you a mini link and a direct link to the file(wich are the ones that you'll need for your demo and picture).
Use the mini link given when you upload your demo (the first link that appears). Just copy that and paste it into your RHG page .
Now for the picture, you must upload the file to fileize (consider that t's size must be 150x150 for the RHG character), but this time you must copy the
direct link to the file, wich is the last link that appears once you uploaded the file (the one that ends with jpg/png/gif etc..). Now to make it appear as a picture on forums, type it like this:

Delete the obvious.
That way it'll appear the picture on your RHG page. I hope this helped, feel free to ask any kind of question about this if it wasn't clear or if you still have a doubt :3.