Yeah though those are for images you upload yourself through that uploader. The images in your signature overall can't exceed 1mb. If that makes since. Just a tip, it's better to upload any of your signatures to a image sharing site like imgur or photobucket instead of the uplaoder in the control panel or get your signature images from another website such as imgur,tumblr,etc. Images uploaded using the uploader in the CP usually get compressed, especially if over 1KB. Images from other sources usually retain their quality.