You have to make sure the images are uploaded somewhere and use absolute URLs to link to the images.

kindly upload the image on a public or private server whatever you may choose which would help the gmail to locate the image from the web

Check to see where the images are located. They may be stored in a private area or on a local computer. If that's the case, the reference link won't work for others.

Also, note that many mobile users have images turned off by default. Be sure to include textual description of any images in the signature so they can determine if they want to load images or not.