Getting map details on zooming

I have seen some maps lately (.jpg, .gif etc), the surprising thing is upon zooming the image datails become clearer, I use qgis and mapInfo for GIS and even after saving my mapInfo project to (.jpg and co), I still do not get the details upon zooming. I know a high detailed/pixel map will provide precision upon zooming but after removing the picture layer before saving with mapInfo, I was expecting everything to be correct, but it was not.

Am I missing something? What can I do? Any suggestions are welcome.