1. A method of shared screen verification, comprising: establishing a desktop sharing session between a publisher device and a viewer device, during which the publisher device renders a publisher display and the viewer device renders a viewer display that corresponds to the publisher display; capturing, at a server device, first framebuffer data for a frame of the publisher display, wherein the first framebuffer data is captured from a first framebuffer at the publisher device and the first framebuffer data corresponds to pixel-based information used to render the frame at the publisher display; separately capturing, at the server device, second framebuffer data for a frame of the viewer display, wherein video content of the frame of the viewer display corresponds to video content of the frame of the publisher display, wherein the second framebuffer data is captured from a second framebuffer at the viewer device and the second framebuffer data corresponds to pixel-based information used to render the frame at the viewer display; based on the first framebuffer data differing in resolution from the second framebuffer data, adjusting, at the server device, resolution of the first framebuffer data, the second framebuffer data, or both the first framebuffer data and the second framebuffer data to generate processed first framebuffer data and processed second framebuffer data that exhibit a consistent display resolution so that the processed first framebuffer data and the processed second framebuffer data are capable of being compared to each other; defining one or more pixel regions of the frame that identify a common display area for the publisher display and the viewer display, wherein the defining comprises: identifying a first N-by-M pixel region of the processed first framebuffer data, wherein N is a nonzero positive integer, and wherein M is a nonzero positive integer: and identifying a second N-by-M pixel region of the processed second framebuffer data, wherein the first N-by-M pixel region and the second N-by-M pixel region correspond to a common display area for the publisher display and the viewer display; and determining, at the server device based on a matching analysis of the processed second framebuffer data for the defined pixel regions of the frame and the processed first framebuffer data for the defined pixel regions of the frame, a score that indicates shared screen display quality of the defined pixel regions of the frame rendered on the viewer display and the publisher display, wherein the score indicates an extent to which the second N-by-M pixel region of the processed second framebuffer data for the defined pixel regions of the frame match the first N-by-M pixel region of the processed first framebuffer data for the defined pixel regions of the frame.