Either I have forgotten or they changed.

The way .gif and other images are supported in comments has technically remained the same for a long time. You just use the .gif or .jpg or .png url somewhere in the comment text and it automatically becomes a click-to-show image. The new Add Image button just makes it easier to get these links correct and preview the image ahead of time. It automatically changes an image page url (imgflip.com/gif/abcd) to a direct image url (i.imgflip.com/abcd.gif)

In the past there was a way to post gifs in comments with the "click to show" available. For the life of me I cannot remember how to do this. Thank you for helping if you can.

I had the same question but have been too lazy to ask.

The link starts like this: imgflip.com/gif/42e51j

After the "https://: you add "i." in front of imgflip.com
Then you remove: "gif/" and add .gif to the end.

GAH!!!! The "i" is where I was messing up. Thank you!

I screwed up about 10 times and Memedave (I think) was getting annoyed because he kept getting notifications from me that said deleted lol.

wow