A pop up I've never seen before...

i hope this is okay to post here...
im trying to make an animated icon where i have the original picture but i want to add words to it...i dont want the words to be on the picture i want it on a black background...i have the black background and the words on the black background and i want to move it to the picture but the text is being dividing it up as a new layer which i understand i was just hoping i can do it differently...but the real real reason for this post is because of this:

what does it mean and how do i do it?