I was wondering if there is an online resource that posts pictures about which ema, omamori, and omikuji each Japanese shrine has. (Not a guide that talks about what ema and omamori are). Some shrines have particularly beautiful or unique ones and was hoping to plan some of those shrines into a future trip. A website in pure Japanese is fine.
I don't think there will be something that covers the entire country simply because that would be an exceedingly large number of places and the offerings will also change (for example themed around the current zodiac animal). You are more likely to find lists of particularly famous / unusual / recommended locations for a particular area, or on a particular theme. If you first decide on a general location you want to visit and then look for information on places in that area it will be far easier.
For example (mix of individual blogs, travel-related sites, etc):
Ema in Kyoto (Japanese)
Cute Ema in Tokyo (Japanese)
Omamori in Tottori (English)
Omamori in Tokyo (English)
Omamori for love (English)