Structure Data Testing Tool – Error WebPage Error

After installing and setting up Schema plugin, filling out all in Schema>Settings, I go to use Structured Data Testing Tool and get 1 error:

WebPage
1 ERROR
0 WARNINGS
expand_less
@type
WebPage
url
https://cotswoldgiftware.com/
cancellogo
https://i2.wp.com/cotswoldgiftware.com/wp-content/uploads/2017/03/Cotswold_Giftware_Logo424x96.jpg?fit=424%2C96&ssl=1 (The property logo is not recognized by Google for an object of type WebPage.)

I have no idea what this means, what the effect is, and how to resolve? Can you please help me, new to this.

Site: https://cotswoldgiftware.com/

Thanks in advance, Chris