I am not sure if you have the death index from online - but on the CD it gives the exact date - and this is presumably your South Brisbane (Dutton Park) man Henry Johnson father William Johnson (no mother given) died 22 Aug 1907 Ref 1907/B008466
On rare occasions I get to the cemetery, but cannot guarantee if/when. Often it is possible to see from the BCC image if a grave has a headstone - sadly with this one it seems impossible to tell.
Given that a father's name is provided, the informant must have had some information on the deceased, so a death certificate may provide information. Alternatively, if you have access to a library or LDS centre with the Qld BDM data on fiche, you could check for the death of Emma Yeo, to see if the parents are likely to be related - AND of interest perhaps is this marriage
Emma Johnson married Alfred Yeo 25 Mar 1895 B017294, so Emmaand Henry could be father and daughter