Solving Riddlers Riddles in Batman Arkham Asylum?

Some of the riddles i have come across are easy enough to solve, but actually arent. For instance, in Botanical Gardens, the answer is the bench, the plate on it says wayne, but when you scan it tells you it is to small, wtf? also the wayne logo off in the distance in gotham or the family photograph, what do you have to do to acquire these?