Way to display images from library to all players

Hi there, new dm who just purchased a subscription to roll20. I'm trying to figure out a way to display images to all players, similar to the shift + z trick. Basically, I know that clicking on an object on the map and pressing shift + z will pull up a zoom window on the object for all players. Is there a way to do this for images that are not part of the map? If there isn't, is there a way I can get images to pop up from another map (ie not the one the players are on)? That way, I could keep all of my npcs and other images in one place instead of having to put tons of images on the gm layer on every map. 

You can put images in the chat (regardless of where they are hosted) with: [x](IMAGE_URL#.png) You can show images to all players using shift-Z, and you can do that with images on the GM layer, so they wouldn't be visible to players until you hit the key combination.

Thanks for the response. Putting them in the chat is less than ideal. Right now, my plan is to copy relevant images onto the gm layer of the currently active map. This is tedious though and involves a lot of copy/paste and delete after its done.  I just want a single place to store my images so that when I shift + z them, they will take over all of my players' screens. Does something like this exist in the API? If so, do you know what call I need to make? 

The API does not have access to the shift-Z functionality. You can also put them as the image on a handout and then show it using the button on the Handout, or by dragging it individually to the names of players.

Well that's a shame. Thanks for the quick response. 

I nearly always include a 1-2 cell margin around my map pages, concealed with regular Fog of War. I throw stuff like that in there, so it's handy but not visible. The margin also reduces a display bug that sometimes causes a map to "stick" to the side of the viewing area.