A nifty little feature of the Yealink IP Phones the ability to display the contents of the LCD via the management page.

Access the web management page, and after authenticating, change your browser URL to http://IP_of_phone/screencapture. Refresh the browser to update the capture.

This works on the following models: SIP-T48G, SIP-T46G, SIP-T42G, SIP-T41P, SIP-T29G, SIP-T28P, SIP-T27P, SIP-T26P, SIP-T23G, SIP-T23P, SIP-T22P, SIP-T21P E2.