I am not sure I understand your problem 100%, but I will have a go at it.
Here is what I understand from your description:
You have some images (jpg) that appear fine in your ABM app.
Then you edit these images with an image editing program and you save them (with the same image name) in the appropriate ABM app folder.
However, the ABM app does not show the new version of the images - it keeps showing the old version of the images.
If this is the case, then it is something that happens often and it is caused by image caching. Your ABM app sees that it needs to load an image which it has already loaded in cache (since the name is the same). So, it ends up loading the cached version (which is the previous version of your image).
Clearing the cache is not a viable solution, as you have no control over what each user does at their browser.
My solution: I change the name of the image temporarily (e.g by creating a temporary copy, adding datetime info in the image name) and tell the ABM app to load this new image.