By the miracle of curl, I see the link I posted does a 302 redirect, and the destination includes these header tags, amongst a great deal else:
<meta property="og:title" content="yorkshire (test) · Apr 27 – May 2, 2014 📸">
<meta property="og:type" content="website">
<meta property="og:url" content="https://photos.google.com/share/AF1QipP-hhF_ef_wWDLFBBgdrtFoZlNkLz4RRnX3\
EoLJG6KcJ2bDGnWk1tPmId_E73Im6A?key=aW9pN1pUSXJDcnJicmFRM0otS0otd18wUnVaTllR">
<meta property="og:image" content="https://lh3.googleusercontent.com/pw/AP1GczOdt22cIOKru3pFYRjCaNDBJm2BX\
kFI_fm_6SzmN8Ur48q2ebtH5rL4YsYfau9cAQkL-fq0LR45SSS_KL15pWsPZBHnYLk3pzpr7YQliOucWn1WfrK7=w600-h315-p-k">
<meta property="og:image:width" content="600">
<meta property="og:image:height" content="315">
<meta property="og:description" content="Shared album · Tap to view!">
<meta name="twitter:card" content="photo">
<meta name="twitter:site" content="@googlephotos">
...
<meta property="og:site_name" content="Google Photos">