Hi Amanda.
As Richard would say, tray it.
Store the image once note the size of the DB file. Add it ten times and check the size again.

If the picture type on the property sheet is "Embedded," it will use extra space.  If it is "Linked" or "Shared," it won't.  So it is usually best to embed small files and link or share large files.

I can tell you how it's supposed to work. If you insert an image using the Image Gallery, then it's supposed to save the image once in the database in the Image Gallery. If you use it on multiple forms and reports, it's still using the same image. Now, I have not independently tested this to see if it actually saves space, but it would be something you could easily do. This is useful for company logos, for example, where you're going to use it on multiple forms and reports, so someone should test this and let me know. Just be sure, once in a while, to purge your Image Gallery if you have images in there that you're no longer using.