Your customers see your profile picture when they are asked to Vouch. They don’t see the photo of the job that you took.
Make sure your profile picture has a nice head shot of you. Look through your photo library and see if you can find a head shot picture of you that reflects your work demeanour.
Crop the image when you select it so that it shows your face and shoulders.
Please don’t select an image which has other people in it or has you in the distance.