Can't crop an image "live" on the canvas while I'm working on a composition??

This is driving me crazy... when I'm working on a layout using different assets (text, photos, other assets) I can't figure out how to crop a photo to the size I want after I drop it into the canvas. I swear I was able to do that before, but the only thing I see now is "resize" and it wants to resize the whole canvas.... I've resorted to exiting what I'm working on, opening a square canvas (or whatever aspect ratio I need the photo to be), bringing the photo in, saving that as a new file, then going back into the canvas to drop the newly created cropped photo in. This can't be right...