What if you created a 'silence' costume? You would obviously have to do it whilst keeping an eye on the silence but would people then forget you too? When the doctor brought up an image of one in the TARDIS they all forgot it
If you did create a costume or some sort of model of one and didn't forget it then you would know what they looked like all the time
I should be the next companion

And of course, whatever holds the image of an angel is itself an angel! If the two concepts are related, then whoever starts looking like a Silent becomes a Silent.

What if you're dressed as a silent and look into the eyes of an angel?

What do you think Doctor Who really is?

It's a plan to get us used to seeing waht Silence look like so we are ready for the final battle. Why didn't Judgement Day happen last month - postponed till October - cos Doctor Who is off air in summer and they knew we weren't ready.