Two different species of Eucalyptus?
Nope. These two shots are of the same tree growing in Floreat*.
These are the juvenile leaves (click photo to enlarge)...
…and these are the mature leaves.
A lot of Eucalypts do this and it's why trying to identify them by anything other than their mature foliage is hazardous.
Where it gets even trickier is that some have mature leaves that look like juvenile leaves!
Ah, the wonder of nature :)
* It was a Tasmanian Blue Gum (Euc.globulus) I think