White Cube with Heart Symbols — Gray, Neutral

1680 × 1050

White Robot with Red Light — Gray, Neutral

1920 × 1080

Portal Gun Device — White, Neutral

1024 × 768

Portal-themed digital artwork

2560 × 1440

Anime Character with Long Hair — Blue, Dramatic, Long White Hair

1280 × 1024

Cat and Dog in Portals

1920 × 1200

Blue Robotic Hedgehog

1920 × 1200

Boy Hugging Creature — Green

1024 × 768

Cave Johnson Character — White

1600 × 1200

Purple Robot Transformer — Dramatic

1680 × 1050

Red Robot Character — Dynamic, Digital Art

1600 × 1200

Four People Near Building — Green

1600 × 1200