He noticed the Gunners failed to water the Emirates pitch ahead of the match - on what was one of the hottest days on record.
Jackson said: "After 20 years under the same manager, they [Arsenal] didn't water the pitch before the match or at half time, which is very unusual. It didn't do them any good thankfully.
"When Tony Pulis was at Stoke you would walk on the pitch before the game and couldn't see your feet, it was so long.
"But most managers now want it wet and short as the ball travels quicker, they tell us. The pitch is where their final work gets done, so if something is not right, we listen to them."
On Guardiola, he added: "Pep's attention to detail is phenomenal – something I have never experienced.
"When I first started Peter Reid was player-manager, a fantastic guy, but a very different landscape. If Pep wants a bit more water, or the grass a bit shorter, it's for a reason."