Recently active topics in Mento tagged with edit

I usually want to post an item to a channel, with an image. Often the UI leads to me forgetting to grab my image, and "sending" to a channel. I can't find a way to go back & select an image via editing the post. Is this function available?

I'm very confused about Sending to a channel and not being able to SAVE to a channel. The Save tab does not offer channels, does it?