Hello,
For some reason, adblock is blocking images using pattern ".*s300/x300/y600/.*_300_300_600.*" (maybe just a subset of this)
Exemple pages :
http://cartometro.com/cartes/metro-tram ... 149&zoom=2
http://cartometro.com/cartes/metro-tram ... 055&zoom=4
Adblock For Chrome
Version 4.32.1
Windows 10 x64
Network inspector :
carto_metrolondon_2_300_300_600.png?x3.10 (blocked:other)