Twitcaps is a webpage that lets you search images on twitter. Pick a theme or enter a word and you will see lots of and related images.
The main advantage of this application is that it is constantly updated, so you will always get new pictures.
Use filters to get good results. TFilter by country, language or place
Each image has been published with the message, so that you know the context and the author.
With no doubt Twitcaps, there is really useful application to find the latest images of a photo.