Hi!
For the 1st question, it works (i believe) the same as steem
I just post the 'social link' that I find here >
i.e.
https://giphy.com/gifs/nature-earthday-PipLR8qMID6XR3L5cY/media
https://media.giphy.com/media/PipLR8qMID6XR3L5cY/giphy-downsized-large.gif
It has to end to .gif
Regarding the 2nd, I have not figured it out yet ... I will wait if someone else responds