A ghost one?
But joking aside,
Yeah, that would be conclusive. But it is fascinating how a fuzzy set of not-quite-clear-enough-to-even-call-them-details can fool you. (Well, fool, ME, I am not confessing on behalf of anybody else.) On looking at the pic initially, I did notice the blue thing is actually on the windowsill, but then went astray. But looking at this circled bit
that looked to me enough like writing to conclude the face was in fact a face, but on a TV screen ... Read even more