ok think about this

2 guys stand at a bar with a Tshirt on both in the same position holding their pint
one guy massive arm -- big chunk of meat no definition
second guy slihgly smaller arm but loads of defination, veins, muscle fibres

you will autimatically be drawn to the second guy and think he is the most muscular

leaness = Shape, definition, veins, striations

another example
way back when -- i used to go to night clubs wearing a baggy shirt with a tight tshirt underneath (this was before you could get in with a tshit)
so i get in--take my shirt off and stick it in the cloakroom -- i get laods of attention etc -- even used to walk up to the bar and the guy would ahve my drink ready for me because i stood out so much

anyway i am outside at the end of the night going home and we get talking to a guy we met in the club -- he goes ' fuck did you see that massive guy with the tight tshirt on'

i go ' yeah it was me'

again -bodybuilding is about creating an illusion -- take for example baggy shirt me was big muscles and tight shirt me is definition

I went to a bodybuilding comp years ago and realised after 10 minutes i was stood next to Dorian Yates who was Mr Olympia -- he just looked like a big guy in a shirt --yet when he took his shirt off to guest pose he looked phenominal

get my point?