The blond guy (David) looks smaller and weaker then the left one (Goliath) ..... but is it true?
David and Goliath | the vintage painting of two funny men taken from a German/French magazine
When you lay the figures next to each other in the same direction it appears that the one in front is bigger ..... though they are really of the same size.
Also watch :which bikini lady is bigger? , another great relative size optical illusion.