javascript - website event listener(?) to change image from url post -

i proof-of-concept following: post message file name in website (this post many types of devices, , anywhere). website 'gets' message , loads file matches incoming filename. keeps 'listening' can continue pass filename strings other images load.

for test, displaying jpegs in website (assume of images exist on website).

code solution great, knowing can greedy - terms should looking accomplish may google , cobble something?