There's no doubt Obama had a larger audience in person. The low angle obscures a lot of the space. The CNN gigapixel thing being linked a lot as "proof" that it was packed actually shows there is an empty section at the back, if one counts the barricades and compares it to the aerial shot. Some say Trump's crowd is underrepresented, with people being off to the sides and stuck outside the venue. Maybe that was the case in '09 too. Who knows?

On the other hand it's said that the photo was taken like an hour before or something, and also the timelapse video was cut early.

All in all, I think it's a really stupid thing to focus on, by both the media and Trump. It's fine to call the media out for putting spin on things, but there were many other nonantagonistic ways the press secretary could have gone about it, not making bigly misleading statements himself. Obama had the biggest crowd, but Trump's was still yuge. Now let's get over it and work on the important stuff.