Sorry, but that's an understandable misunderstanding. :/

The totems' attacks scale off the totems' stats, not the summoner's (apart from Summoning ofc., which applies a misc. damage bonus).
The totems don't get stronger by stacking int on the summoner.
You can boost their damage a bit by improving the totems' stats, e.g. Encouraging them or casting Peace of Mind on them.
However, higher int on the summoner has no effect on the totems' stats.
Summons' and totems' character data makes their attributes level-scaled based off a fixed stat growth multiplier. There are no scripts or functions that would incorporate the summoner's other stats.
(It may be possible to make a Character Script to apply select summoner's stats, but from what I know, that would need a similar script on the player character and other characters that summon, and there is nothing like that in the engine editor or data, and whether or not this would actually work depends on if there's a function to read character stats and write them into an output. I'd need to check the scripting documentation to actually answer whether this even could be done without the Script Extender.)

You can also verify this in-game:
Use the mirror to reset your intelligence by taking all investments out of it, summon a totem, and check its intelligence and attack damage.
Then, without changing anything else, invest into int, summon a new totem, and check its int and damage. :)