There are various ways to reduce the size of an image. One way is to simply resize the image to say 80
600 resolution. It makes little sense to view images when they are 160
1200 as hardly anyone has their screen set that high.
Another way to lower file size if simply reducing the resolution does not help is to increase the level of jpeg compression the file is saved under.
With some care you can get a 700+KB file down to under 100KB with some tweaking and little quality loss.