[rayvio]

there's a few factors. even in recent adventure games the graphics are often behind those of other modern games (not that I'm complaining, story and gameplay are by fare more important) so "look at" can be very important in informing the player of detail that can't be seen normally
also subtle hints can be slipped into the description, or jokes. even non-comedy games can sometimes benefit from a little humour here and there
but if all "look at" tells you is things you can already see then yes, it's rather redundant