The Cleric, needs to be in range for the spell to work, but you can cast counterspell if you see either of them casting a spell:
Counterspell has a casting time of:
1 reaction, which you take when you see a creature within 60 feet of you Casting a Spell
So you would think that you would need to be able to see a real creature casting a spell to have this work. However, Jeremy Crawford, 5e lead rules designer, responded on twitter to two questions about this topic on twitter.
Q1: Hi!! Quick q: Trickery cleric uses Invoke Duplicity to cast spells
from. The illusory image that ID [sic] creates is then counterspelled in the
process of casting a spell; does the counterspell stop the spell cast,
or fail as it's an illusion?
A1: Invoke Duplicity doesn't protect a cleric from being
counterspelled if the person casting counterspell can see the
cleric/illusion and the cleric is within 60 feet of the caster.
source
and
Q2: Does seeing the illusion from Invoke Duplicity count as “seeing” the actual Cleric?
A2: Seeing the illusion created by Invoke Duplicity isn't the same as seeing >the cleric. However, seeing the illusion is sufficient for some things in the >game, like counterspell, that are triggered by seeing processes (seeing the >cleric casting a spell, for example).
source
Based on this ruling, if you can see either the illusion or the cleric themself in the process of casting a spell, you have a valid trigger for counterspell. This is even though the illusion isn't a creature. With that being said, Invoke Duplicity allows you to cast the spell as if you were in the illusion's space, but the Cleric is still the one casting the spell. Even if you react to the illusion appearing like it's casting a spell, the cleric needs to be in that 60 foot range for the counterspell to be successful, since they are the one who is going to be counterspelled.