AtStudioD

Your question about how to upload your card to the challenge gallery. I believe there are instructions on the main page of the challenge.
How I do it.
First I up load my card to my gallery. I use the "Upload a card" on the left side of the page under "Around the Site". I usually pick "Member gallery"
Enter all the info about the card (ink, paper, description, etc) Once you save it into your gallery, I open the card in my gallery.
At the top of the screen, where the web address is, highlight the address.
Under the "Edit" tab, pick "Copy"
Go back to the challenge forum you want to display your card. Go to the place where you post (at the bottom of the page) and type what you want to say. Move your curser to the top of the screen. Under "Edit" pick "Paste". The address should appear in your comment. Submit your comment. When it posts it should be in grey. Hope this helps.