WestEndBoy,... You Sir, seem to be very, very correct!
I take it you're referring to this colourful wall,... on (mezzanine) pay collector concourse level at south-end by elevator directly under the wait area for southbound bus.
View attachment 122837
https://www.flickr.com/photos/castelmar/16243719316
Interestingly, behind that colourful "knock-out" wall, seems to be an empty room? mechanical room, vent room, etc,... in the above photo, the grey door opposite the elevator might lead to the room in question, the grey door has a black label tag near the top,... which *might* indicate what's inside this room!,... hmmmm,....
View attachment 122838
http://bgoldenco.com/portfolio/dufferin-station/
http://urbantoronto.ca/database/projects/dufferin-station-modernization
For this proposal, P2 resident parking doesn't seem as promising,... but the adjacent northeast corner of P1 Visitor Parking Level look like this, currently no TTC direct connection tunnel but public "Galleria Access" elevators and stairways from southwest of Bloor and Dufferin - P1 level corner Mech room is probably vent room and lockers can be moved around to make room for underground pedestrian tunnel access:
View attachment 122839
Obviously direct subway connection would help developer sell for higher premium price (about 15% more). The cost of an underground pedestrian subway tunnel here might be around $15 million including TTC connection fees and all. So why didn't developer draw it in? Likely still under negotiation with TTC or at least kicking the tires, also might try to negotiate some of the cost into Section 37 Community Benefits,... this proposal is still very early in development application and will likely take about 2 years for settlement and final report,... longer if OMB,...
Note: Since physically the Bloor-Danforth subway line is usually north of Bloor & Danforth (Sherbourne Station exception), there's usually no underground pedestrian connection from south side (Manulife Centre at Bloor-Bay is more underground PATH connection - southeast corner of Yonge-Bloor at Hayden St is for Yonge line),... thus, this development might be the first development with direct TTC connection along south side of Bloor or Danforth.