The Holland Lop pose is almost entirely structural. A well-bred and nicely typed animal will be much more willing to pose and easier to pose because their body type allows for it. It's simply easier for them to pose.
Rabbits that are longer in body, low in shoulder, long in bone, etc. will typically be more difficult to pose because they're not built for it.
If you're having a lot of trouble with posing, it could be that the rabbit's type makes a correct pose difficult. It's not impossible for a beautifully typed animal to be a "table hugger," but I've found that generally the closer they are to the standard, the more willing the rabbit will be.
Beyond the build of the rabbit, like mentioned, it just takes practice to get the rabbit used to being messed with.