In FP1, Alex Albon was an impressive third fastest, and the Thai/British driver then underlined the speed of the car by repeating the performance in FP2, albeit helped by Ferrari's Charles Leclerc failing to complete a lap.
However, while Albon has been an occasional visitor to the top 10, what really caught the attention of rivals was the fact that rookie Logan Sargeant was fifth fastest in FP2 in what was by far the best showing of the American's season so far.
Williams introduced a new aero package in Montreal, where Albon finished seventh on a track where the updates – aimed at high-speed corner performance – were not expected to provide much benefit.
The revised car's potential was perhaps not obvious over the Austrian sprint weekend, although Albon qualified 10th and had a solid race to 11th.
"We need to go and have a look at the data and try and understand it," Robson told Motorsport.com regarding the Silverstone form.
"We did think we'd be a little bit better here back at a high-speed circuit with the package we fitted in Canada. I don't think we really saw the best of it until perhaps here.
"In Austria, it's so tight, such a short lap. So even if the performance is there, it's so easy to get pushed down the timesheet, make a mistake, go off track.
"So I think the performance was quite good in Austria. There's a lot more to getting a good result there than just pure car pace.
"But nonetheless, it has been a better day than we were expecting. We've got to go and understand that. It's just the high-speed cornering performance, I think."
Asked if the Friday pace would change the team's approach heading into Saturday, Robson stressed that the focus would be on the bigger picture of working out why the car is so suited to the track.
"I don't think it changes anything we do," he said. "In fact going through the data and stuff tonight is probably more important than when we have a difficult Friday.
"It's more important are really to understand why it's gone well, and make sure we don't muck it up!"
Albon echoed Robson's sentiments about the Silverstone pace not being predicted.
"It was a bit surprising in some ways," he admitted. "I have to say unexpected, we're not playing around doing weird things. It's just a normal day for us, and we crossed the line and we're in the top three. So a bit in some ways head-scratching.
"But at the same time the car feels good. We've got an upgrade on the car that we've had for two races now. At least on the simulator, it's shown to be a bit more effective in the high-speed than the low-speed.
"And we haven't really had too many high-speed tracks in the last two races, and it's the first time we've seen the package working on a quick circuit. It's looking quite good, but we've got to keep ourselves grounded. It's chipping away."
Albon noted that strong wins are an issue this weekend: "The way that it is this weekend, it's so strong, it doesn't feel good around here. It feels terrible for everyone, but clearly less terrible for us than others."
