The inurl:axis-cgi/mjpg/video.mjpg syntax you're referring to is often used in the context of searching for Axis camera feeds that use MJPG for video streaming. This specific URL path is typically used to access the MJPG video stream from an Axis camera.
Putting it all together, "inurl axis cgi mjpg motion jpeg hot" seems to relate to accessing live video feeds from Axis cameras using Motion JPEG encoding over the web, possibly through a CGI interface. inurl axis cgi mjpg motion jpeg hot
<html> <body> <img src="http://camera_ip/mjpg/video.mjpg" width="640" height="480" /> </body> </html> The inurl:axis-cgi/mjpg/video
This Google search operator limits results to pages that contain the specified text in their URL. possibly through a CGI interface. <