That's what Leonardo said.
You counseled him about that didja? :-D
This may be an urban legend, but the story goes that DaVinci was working on the last supper. He spent an incredible amount of time working on the cup in Christ's hand.
An associate came in and said "The cup is beautiful, I can't take my eyes off of it."
DaVinci immediately took a brush and wiped clear all traces of the cup.
---- Could be legend, but it's a cool story. Feel free to use it for sermon illustrations. ;-)
------ But that also means I have to tell one of my favorite jokes...
Q. What did Jesus say to the disciples at the Last Supper?
A. If you want to be in the picture, sit on this side of the table.