I would say that technically the yellow one would be more likely to get a ticket in July.
Especially if that post is the parking limit. The regular Green Hornets around there are pretty good, but when they go on vacation, their substitute can be more picky, as they're usually trying to earn a full-time spot.
Don't forget if the black bike parks too close to 90, that box will hang over the sidewalk. If everyone is parked at the same angle say 75 degrees, it doesn't make a huge difference of space between 75 and 90, and it usually makes it easier to get out and rolling. Also, the longer bikes don't stick out into traffic. If you ever park on Mercer Street don't park at 90 degrees. Freight trucks like to park on the opposite side of the road and eat lunch/chill/etc, and taxis use it as a shortcut. What this frequently means is that cars are squeezing between the truck and the bikes with a couple of inches of clearance on either side. A bike that sticks out is going to get hammered.