Screenshots.getScreenshotForURL was modified to return an object instead of a string in the patch for Bug #1436615 (https://github.com/mozilla/activity-stream/blob/7e544945fbe0cba46eba9387e4c593e98d8f9f55/lib/Screenshots.jsm#L45). We need to handle those blob objects in the TopSiteLink component as well because it is treating the inputs as base64 strings: https://github.com/mozilla/activity-stream/blob/7e544945fbe0cba46eba9387e4c593e98d8f9f55/content-src/components/TopSites/TopSite.jsx#L89. I am working on a patch for this at the moment. Thanks :mconley for bringing this up!

Commit pushed to master at https://github.com/mozilla/activity-stream https://github.com/mozilla/activity-stream/commit/b92c8c6068e5f9bb8b8df7d2b2bcbfe7226a752e fix(topsites): Share blob handling utils with top sites and cards (#4198) Fix Bug 1467485 - Missing screenshots for TopSiteLink components in Nightly Signed-off-by: Jay Lim <6175557+imjching@users.noreply.github.com>

I'm still seeing this in latest Nightly, is it expected?

It's still waiting on review in bug 1467858.

This issue is no longer reproducible on the latest Nightly (62.0a1 - Build ID 20180615100050). Now each "Top Site" has its screenshot successfully displayed. Verified on Windows 10 x64, Ubuntu 16.04 x64 and Mac 10.13.