You're making a mountain out of a molehill. Please consider:
1) Google's Image Search is not the first such service -- there are some that have been around for years (TinEye being the largest and probably best known.) So to whatever extent such services represent a threat to eBay sellers, that threat has been around for much longer than you've been aware of it.
2) Since many product pictures, particularly those used by dropshippers, are themselves manufacturer-provided or otherwise recycled, the odds that you will somehow be "outed" are perhaps more slim than you might think.
3) Losing your supplier to a customer is an unfortunately extent possible side effect whenever you deal with a no-MOQ supplier who has no barriers to entry at all for customers. This is just one of the huge number of reasons to avoid dropshipping as a business model, since there's little to nothing to stop any customer of yours from finding out where you get your product and just ordering direct.
4) You could always use other images than those provided by your supplier, and instantly remove this problem (to whatever degree it actually is a problem.)