Text/Description of Gallery

Hi guys,
You know when you create a new gallery, you can add text and then upload the imaged for the gallery. That bit seems ok and I can see my images in the gallery as expected. What I can’t see however is the text that I typed in when I added the new gallery.
Where do/should you see this?

Also, I notices that my gallery is a little slow. I expect to have a lot of images. What are you recommendation re image size so its not so slow?

Thanks very much,
Racheal