WWII Aircraft Recognition Posters

Why do web designers make it difficult to see the actual photo? They've gone into the trouble of putting an enlarge icon (and needed code), but it still displays a small window.

I can understand that it's there to deter simple users from getting access (especially since the posters are for sale), but if they don't want to show the full resolution file then don't put it online and use a low-res one :-)

https://store.pacificwarmuseum.org/uploads/products/navyairc...

https://store.pacificwarmuseum.org/uploads/products/ArmyAirc...

https://store.pacificwarmuseum.org/uploads/products/japanese...

I grew up with a Uk version from probably ww1 in my family’s place.

Edit. This one https://www.dpvintageposters.com/posters/original-british-ww...

Learned this weekend: among the reasons soldiers needed to identify the planes by sight - the B-29 had a computer-assist turret that adapted to target range and relative velocity. But it could only estimate range appropriately if the gunner dialed in the wingspan of the target so that dialing the reticle to "pin" the target wing-to-wing corresponded to the correct range.

Training film: https://www.youtube.com/watch?v=mJExsIp4yO8