You'd also need to check the specs on the switching transistor Q1 and look at the track layout to see if there are adequate creepage and clearance distances for 230V mains supply. Even so, at best it would be indicative of a 230V rated design, and would *NOT* guarantee it wouldn't go bang! or rapidly degrade if fed with 240V AC.
*MOST* manufacturers with wide voltage range capable PSUs are happy to claim that on the exterior ratings label. If it doesn't say something like 100V - 250V AC on the label, odds are it isn't capable of operating at a significantly different supply voltage without possibly extensive modifications.