The former Arsenal man, who moved to the Robins from Ipswich over the summer, set up both goals in Tuesday's 2-0 Capital One Cup win over Gillingham.
Emmanuel-Thomas beat two Gills players on the by-line to set up Sam Baldock for an easy tap in after 21 minutes.
His deflected 66th-minute shot then fell into the path of Jordan Wynter for City's second, and O'Driscoll was far from surprised by his stand-out performance.
"I've worked with him before, I think there were a few eyebrows raised when we took him," said the Robins boss. "But I want to look at things he can do rather than things he can't.
"Everybody in football knows that Jay has talent, it's just can he apply himself?
"If he can do that then people will sit up in the stands, the scouts when they see him chasing back and winning headers.
"They are not going to be surprised when he beats three men and puts it in the top corner.
"We have him in the side and he creates stuff for us which we need. We've got to make sure we encourage him.
"Twelve months ago I watched Bristol City get beat by Gillingham at home, so it's nice to learn from those mistakes and put on a performance that warranted the win."